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freebsd-nq/sys/vm/vm_phys.c

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Add a new physical memory allocator. However, do not yet connect it to the build. This allocator uses a binary buddy system with a twist. First and foremost, this allocator is required to support the implementation of superpages. As a side effect, it enables a more robust implementation of contigmalloc(9). Moreover, this reimplementation of contigmalloc(9) eliminates the acquisition of Giant by contigmalloc(..., M_NOWAIT, ...). The twist is that this allocator tries to reduce the number of TLB misses incurred by accesses through a direct map to small, UMA-managed objects and page table pages. Roughly speaking, the physical pages that are allocated for such purposes are clustered together in the physical address space. The performance benefits vary. In the most extreme case, a uniprocessor kernel running on an Opteron, I measured an 18% reduction in system time during a buildworld. This allocator does not implement page coloring. The reason is that superpages have much the same effect. The contiguous physical memory allocation necessary for a superpage is inherently colored. Finally, the one caveat is that this allocator does not effectively support prezeroed pages. I hope this is temporary. On i386, this is a slight pessimization. However, on amd64, the beneficial effects of the direct-map optimization outweigh the ill effects. I speculate that this is true in general of machines with a direct map. Approved by: re
2007-06-10 00:49:16 +00:00
/*-
* Copyright (c) 2002-2006 Rice University
* Copyright (c) 2007 Alan L. Cox <alc@cs.rice.edu>
* All rights reserved.
*
* This software was developed for the FreeBSD Project by Alan L. Cox,
* Olivier Crameri, Peter Druschel, Sitaram Iyer, and Juan Navarro.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY
* WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
Refactor the code that performs physically contiguous memory allocation, yielding a new public interface, vm_page_alloc_contig(). This new function addresses some of the limitations of the current interfaces, contigmalloc() and kmem_alloc_contig(). For example, the physically contiguous memory that is allocated with those interfaces can only be allocated to the kernel vm object and must be mapped into the kernel virtual address space. It also provides functionality that vm_phys_alloc_contig() doesn't, such as wiring the returned pages. Moreover, unlike that function, it respects the low water marks on the paging queues and wakes up the page daemon when necessary. That said, at present, this new function can't be applied to all types of vm objects. However, that restriction will be eliminated in the coming weeks. From a design standpoint, this change also addresses an inconsistency between vm_phys_alloc_contig() and the other vm_phys_alloc*() functions. Specifically, vm_phys_alloc_contig() manipulated vm_page fields that other functions in vm/vm_phys.c didn't. Moreover, vm_phys_alloc_contig() knew about vnodes and reservations. Now, vm_page_alloc_contig() is responsible for these things. Reviewed by: kib Discussed with: jhb
2011-11-16 16:46:09 +00:00
/*
* Physical memory system implementation
*
* Any external functions defined by this module are only to be used by the
* virtual memory system.
*/
Add a new physical memory allocator. However, do not yet connect it to the build. This allocator uses a binary buddy system with a twist. First and foremost, this allocator is required to support the implementation of superpages. As a side effect, it enables a more robust implementation of contigmalloc(9). Moreover, this reimplementation of contigmalloc(9) eliminates the acquisition of Giant by contigmalloc(..., M_NOWAIT, ...). The twist is that this allocator tries to reduce the number of TLB misses incurred by accesses through a direct map to small, UMA-managed objects and page table pages. Roughly speaking, the physical pages that are allocated for such purposes are clustered together in the physical address space. The performance benefits vary. In the most extreme case, a uniprocessor kernel running on an Opteron, I measured an 18% reduction in system time during a buildworld. This allocator does not implement page coloring. The reason is that superpages have much the same effect. The contiguous physical memory allocation necessary for a superpage is inherently colored. Finally, the one caveat is that this allocator does not effectively support prezeroed pages. I hope this is temporary. On i386, this is a slight pessimization. However, on amd64, the beneficial effects of the direct-map optimization outweigh the ill effects. I speculate that this is true in general of machines with a direct map. Approved by: re
2007-06-10 00:49:16 +00:00
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include "opt_ddb.h"
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/lock.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/mutex.h>
#include <sys/queue.h>
#include <sys/sbuf.h>
#include <sys/sysctl.h>
#include <sys/vmmeter.h>
#include <ddb/ddb.h>
#include <vm/vm.h>
#include <vm/vm_param.h>
#include <vm/vm_kern.h>
#include <vm/vm_object.h>
#include <vm/vm_page.h>
#include <vm/vm_phys.h>
Very rough first cut at NUMA support for the physical page allocator. For now it uses a very dumb first-touch allocation policy. This will change in the future. - Each architecture indicates the maximum number of supported memory domains via a new VM_NDOMAIN parameter in <machine/vmparam.h>. - Each cpu now has a PCPU_GET(domain) member to indicate the memory domain a CPU belongs to. Domain values are dense and numbered from 0. - When a platform supports multiple domains, the default freelist (VM_FREELIST_DEFAULT) is split up into N freelists, one for each domain. The MD code is required to populate an array of mem_affinity structures. Each entry in the array defines a range of memory (start and end) and a domain for the range. Multiple entries may be present for a single domain. The list is terminated by an entry where all fields are zero. This array of structures is used to split up phys_avail[] regions that fall in VM_FREELIST_DEFAULT into per-domain freelists. - Each memory domain has a separate lookup-array of freelists that is used when fulfulling a physical memory allocation. Right now the per-domain freelists are listed in a round-robin order for each domain. In the future a table such as the ACPI SLIT table may be used to order the per-domain lookup lists based on the penalty for each memory domain relative to a specific domain. The lookup lists may be examined via a new vm.phys.lookup_lists sysctl. - The first-touch policy is implemented by using PCPU_GET(domain) to pick a lookup list when allocating memory. Reviewed by: alc
2010-07-27 20:33:50 +00:00
/*
* VM_FREELIST_DEFAULT is split into VM_NDOMAIN lists, one for each
* domain. These extra lists are stored at the end of the regular
* free lists starting with VM_NFREELIST.
*/
#define VM_RAW_NFREELIST (VM_NFREELIST + VM_NDOMAIN - 1)
Add a new physical memory allocator. However, do not yet connect it to the build. This allocator uses a binary buddy system with a twist. First and foremost, this allocator is required to support the implementation of superpages. As a side effect, it enables a more robust implementation of contigmalloc(9). Moreover, this reimplementation of contigmalloc(9) eliminates the acquisition of Giant by contigmalloc(..., M_NOWAIT, ...). The twist is that this allocator tries to reduce the number of TLB misses incurred by accesses through a direct map to small, UMA-managed objects and page table pages. Roughly speaking, the physical pages that are allocated for such purposes are clustered together in the physical address space. The performance benefits vary. In the most extreme case, a uniprocessor kernel running on an Opteron, I measured an 18% reduction in system time during a buildworld. This allocator does not implement page coloring. The reason is that superpages have much the same effect. The contiguous physical memory allocation necessary for a superpage is inherently colored. Finally, the one caveat is that this allocator does not effectively support prezeroed pages. I hope this is temporary. On i386, this is a slight pessimization. However, on amd64, the beneficial effects of the direct-map optimization outweigh the ill effects. I speculate that this is true in general of machines with a direct map. Approved by: re
2007-06-10 00:49:16 +00:00
struct vm_freelist {
struct pglist pl;
int lcnt;
};
struct vm_phys_seg {
vm_paddr_t start;
vm_paddr_t end;
vm_page_t first_page;
Very rough first cut at NUMA support for the physical page allocator. For now it uses a very dumb first-touch allocation policy. This will change in the future. - Each architecture indicates the maximum number of supported memory domains via a new VM_NDOMAIN parameter in <machine/vmparam.h>. - Each cpu now has a PCPU_GET(domain) member to indicate the memory domain a CPU belongs to. Domain values are dense and numbered from 0. - When a platform supports multiple domains, the default freelist (VM_FREELIST_DEFAULT) is split up into N freelists, one for each domain. The MD code is required to populate an array of mem_affinity structures. Each entry in the array defines a range of memory (start and end) and a domain for the range. Multiple entries may be present for a single domain. The list is terminated by an entry where all fields are zero. This array of structures is used to split up phys_avail[] regions that fall in VM_FREELIST_DEFAULT into per-domain freelists. - Each memory domain has a separate lookup-array of freelists that is used when fulfulling a physical memory allocation. Right now the per-domain freelists are listed in a round-robin order for each domain. In the future a table such as the ACPI SLIT table may be used to order the per-domain lookup lists based on the penalty for each memory domain relative to a specific domain. The lookup lists may be examined via a new vm.phys.lookup_lists sysctl. - The first-touch policy is implemented by using PCPU_GET(domain) to pick a lookup list when allocating memory. Reviewed by: alc
2010-07-27 20:33:50 +00:00
int domain;
Add a new physical memory allocator. However, do not yet connect it to the build. This allocator uses a binary buddy system with a twist. First and foremost, this allocator is required to support the implementation of superpages. As a side effect, it enables a more robust implementation of contigmalloc(9). Moreover, this reimplementation of contigmalloc(9) eliminates the acquisition of Giant by contigmalloc(..., M_NOWAIT, ...). The twist is that this allocator tries to reduce the number of TLB misses incurred by accesses through a direct map to small, UMA-managed objects and page table pages. Roughly speaking, the physical pages that are allocated for such purposes are clustered together in the physical address space. The performance benefits vary. In the most extreme case, a uniprocessor kernel running on an Opteron, I measured an 18% reduction in system time during a buildworld. This allocator does not implement page coloring. The reason is that superpages have much the same effect. The contiguous physical memory allocation necessary for a superpage is inherently colored. Finally, the one caveat is that this allocator does not effectively support prezeroed pages. I hope this is temporary. On i386, this is a slight pessimization. However, on amd64, the beneficial effects of the direct-map optimization outweigh the ill effects. I speculate that this is true in general of machines with a direct map. Approved by: re
2007-06-10 00:49:16 +00:00
struct vm_freelist (*free_queues)[VM_NFREEPOOL][VM_NFREEORDER];
};
Very rough first cut at NUMA support for the physical page allocator. For now it uses a very dumb first-touch allocation policy. This will change in the future. - Each architecture indicates the maximum number of supported memory domains via a new VM_NDOMAIN parameter in <machine/vmparam.h>. - Each cpu now has a PCPU_GET(domain) member to indicate the memory domain a CPU belongs to. Domain values are dense and numbered from 0. - When a platform supports multiple domains, the default freelist (VM_FREELIST_DEFAULT) is split up into N freelists, one for each domain. The MD code is required to populate an array of mem_affinity structures. Each entry in the array defines a range of memory (start and end) and a domain for the range. Multiple entries may be present for a single domain. The list is terminated by an entry where all fields are zero. This array of structures is used to split up phys_avail[] regions that fall in VM_FREELIST_DEFAULT into per-domain freelists. - Each memory domain has a separate lookup-array of freelists that is used when fulfulling a physical memory allocation. Right now the per-domain freelists are listed in a round-robin order for each domain. In the future a table such as the ACPI SLIT table may be used to order the per-domain lookup lists based on the penalty for each memory domain relative to a specific domain. The lookup lists may be examined via a new vm.phys.lookup_lists sysctl. - The first-touch policy is implemented by using PCPU_GET(domain) to pick a lookup list when allocating memory. Reviewed by: alc
2010-07-27 20:33:50 +00:00
struct mem_affinity *mem_affinity;
Add a new physical memory allocator. However, do not yet connect it to the build. This allocator uses a binary buddy system with a twist. First and foremost, this allocator is required to support the implementation of superpages. As a side effect, it enables a more robust implementation of contigmalloc(9). Moreover, this reimplementation of contigmalloc(9) eliminates the acquisition of Giant by contigmalloc(..., M_NOWAIT, ...). The twist is that this allocator tries to reduce the number of TLB misses incurred by accesses through a direct map to small, UMA-managed objects and page table pages. Roughly speaking, the physical pages that are allocated for such purposes are clustered together in the physical address space. The performance benefits vary. In the most extreme case, a uniprocessor kernel running on an Opteron, I measured an 18% reduction in system time during a buildworld. This allocator does not implement page coloring. The reason is that superpages have much the same effect. The contiguous physical memory allocation necessary for a superpage is inherently colored. Finally, the one caveat is that this allocator does not effectively support prezeroed pages. I hope this is temporary. On i386, this is a slight pessimization. However, on amd64, the beneficial effects of the direct-map optimization outweigh the ill effects. I speculate that this is true in general of machines with a direct map. Approved by: re
2007-06-10 00:49:16 +00:00
static struct vm_phys_seg vm_phys_segs[VM_PHYSSEG_MAX];
static int vm_phys_nsegs;
static struct vm_freelist
Very rough first cut at NUMA support for the physical page allocator. For now it uses a very dumb first-touch allocation policy. This will change in the future. - Each architecture indicates the maximum number of supported memory domains via a new VM_NDOMAIN parameter in <machine/vmparam.h>. - Each cpu now has a PCPU_GET(domain) member to indicate the memory domain a CPU belongs to. Domain values are dense and numbered from 0. - When a platform supports multiple domains, the default freelist (VM_FREELIST_DEFAULT) is split up into N freelists, one for each domain. The MD code is required to populate an array of mem_affinity structures. Each entry in the array defines a range of memory (start and end) and a domain for the range. Multiple entries may be present for a single domain. The list is terminated by an entry where all fields are zero. This array of structures is used to split up phys_avail[] regions that fall in VM_FREELIST_DEFAULT into per-domain freelists. - Each memory domain has a separate lookup-array of freelists that is used when fulfulling a physical memory allocation. Right now the per-domain freelists are listed in a round-robin order for each domain. In the future a table such as the ACPI SLIT table may be used to order the per-domain lookup lists based on the penalty for each memory domain relative to a specific domain. The lookup lists may be examined via a new vm.phys.lookup_lists sysctl. - The first-touch policy is implemented by using PCPU_GET(domain) to pick a lookup list when allocating memory. Reviewed by: alc
2010-07-27 20:33:50 +00:00
vm_phys_free_queues[VM_RAW_NFREELIST][VM_NFREEPOOL][VM_NFREEORDER];
static struct vm_freelist
(*vm_phys_lookup_lists[VM_NDOMAIN][VM_RAW_NFREELIST])[VM_NFREEPOOL][VM_NFREEORDER];
Add a new physical memory allocator. However, do not yet connect it to the build. This allocator uses a binary buddy system with a twist. First and foremost, this allocator is required to support the implementation of superpages. As a side effect, it enables a more robust implementation of contigmalloc(9). Moreover, this reimplementation of contigmalloc(9) eliminates the acquisition of Giant by contigmalloc(..., M_NOWAIT, ...). The twist is that this allocator tries to reduce the number of TLB misses incurred by accesses through a direct map to small, UMA-managed objects and page table pages. Roughly speaking, the physical pages that are allocated for such purposes are clustered together in the physical address space. The performance benefits vary. In the most extreme case, a uniprocessor kernel running on an Opteron, I measured an 18% reduction in system time during a buildworld. This allocator does not implement page coloring. The reason is that superpages have much the same effect. The contiguous physical memory allocation necessary for a superpage is inherently colored. Finally, the one caveat is that this allocator does not effectively support prezeroed pages. I hope this is temporary. On i386, this is a slight pessimization. However, on amd64, the beneficial effects of the direct-map optimization outweigh the ill effects. I speculate that this is true in general of machines with a direct map. Approved by: re
2007-06-10 00:49:16 +00:00
static int vm_nfreelists = VM_FREELIST_DEFAULT + 1;
static int cnt_prezero;
SYSCTL_INT(_vm_stats_misc, OID_AUTO, cnt_prezero, CTLFLAG_RD,
&cnt_prezero, 0, "The number of physical pages prezeroed at idle time");
static int sysctl_vm_phys_free(SYSCTL_HANDLER_ARGS);
SYSCTL_OID(_vm, OID_AUTO, phys_free, CTLTYPE_STRING | CTLFLAG_RD,
NULL, 0, sysctl_vm_phys_free, "A", "Phys Free Info");
static int sysctl_vm_phys_segs(SYSCTL_HANDLER_ARGS);
SYSCTL_OID(_vm, OID_AUTO, phys_segs, CTLTYPE_STRING | CTLFLAG_RD,
NULL, 0, sysctl_vm_phys_segs, "A", "Phys Seg Info");
Very rough first cut at NUMA support for the physical page allocator. For now it uses a very dumb first-touch allocation policy. This will change in the future. - Each architecture indicates the maximum number of supported memory domains via a new VM_NDOMAIN parameter in <machine/vmparam.h>. - Each cpu now has a PCPU_GET(domain) member to indicate the memory domain a CPU belongs to. Domain values are dense and numbered from 0. - When a platform supports multiple domains, the default freelist (VM_FREELIST_DEFAULT) is split up into N freelists, one for each domain. The MD code is required to populate an array of mem_affinity structures. Each entry in the array defines a range of memory (start and end) and a domain for the range. Multiple entries may be present for a single domain. The list is terminated by an entry where all fields are zero. This array of structures is used to split up phys_avail[] regions that fall in VM_FREELIST_DEFAULT into per-domain freelists. - Each memory domain has a separate lookup-array of freelists that is used when fulfulling a physical memory allocation. Right now the per-domain freelists are listed in a round-robin order for each domain. In the future a table such as the ACPI SLIT table may be used to order the per-domain lookup lists based on the penalty for each memory domain relative to a specific domain. The lookup lists may be examined via a new vm.phys.lookup_lists sysctl. - The first-touch policy is implemented by using PCPU_GET(domain) to pick a lookup list when allocating memory. Reviewed by: alc
2010-07-27 20:33:50 +00:00
#if VM_NDOMAIN > 1
static int sysctl_vm_phys_lookup_lists(SYSCTL_HANDLER_ARGS);
SYSCTL_OID(_vm, OID_AUTO, phys_lookup_lists, CTLTYPE_STRING | CTLFLAG_RD,
NULL, 0, sysctl_vm_phys_lookup_lists, "A", "Phys Lookup Lists");
#endif
static void _vm_phys_create_seg(vm_paddr_t start, vm_paddr_t end, int flind,
int domain);
Add a new physical memory allocator. However, do not yet connect it to the build. This allocator uses a binary buddy system with a twist. First and foremost, this allocator is required to support the implementation of superpages. As a side effect, it enables a more robust implementation of contigmalloc(9). Moreover, this reimplementation of contigmalloc(9) eliminates the acquisition of Giant by contigmalloc(..., M_NOWAIT, ...). The twist is that this allocator tries to reduce the number of TLB misses incurred by accesses through a direct map to small, UMA-managed objects and page table pages. Roughly speaking, the physical pages that are allocated for such purposes are clustered together in the physical address space. The performance benefits vary. In the most extreme case, a uniprocessor kernel running on an Opteron, I measured an 18% reduction in system time during a buildworld. This allocator does not implement page coloring. The reason is that superpages have much the same effect. The contiguous physical memory allocation necessary for a superpage is inherently colored. Finally, the one caveat is that this allocator does not effectively support prezeroed pages. I hope this is temporary. On i386, this is a slight pessimization. However, on amd64, the beneficial effects of the direct-map optimization outweigh the ill effects. I speculate that this is true in general of machines with a direct map. Approved by: re
2007-06-10 00:49:16 +00:00
static void vm_phys_create_seg(vm_paddr_t start, vm_paddr_t end, int flind);
static int vm_phys_paddr_to_segind(vm_paddr_t pa);
static void vm_phys_split_pages(vm_page_t m, int oind, struct vm_freelist *fl,
int order);
/*
* Outputs the state of the physical memory allocator, specifically,
* the amount of physical memory in each free list.
*/
static int
sysctl_vm_phys_free(SYSCTL_HANDLER_ARGS)
{
struct sbuf sbuf;
struct vm_freelist *fl;
int error, flind, oind, pind;
Explicitly wire the user buffer rather than doing it implicitly in sbuf_new_for_sysctl(9). This allows using an sbuf with a SYSCTL_OUT drain for extremely large amounts of data where the caller knows that appropriate references are held, and sleeping is not an issue. Inspired by: rwatson
2011-01-27 00:34:12 +00:00
error = sysctl_wire_old_buffer(req, 0);
if (error != 0)
return (error);
Re-add r212370 now that the LOR in powerpc64 has been resolved: Add a drain function for struct sysctl_req, and use it for a variety of handlers, some of which had to do awkward things to get a large enough SBUF_FIXEDLEN buffer. Note that some sysctl handlers were explicitly outputting a trailing NUL byte. This behaviour was preserved, though it should not be necessary. Reviewed by: phk (original patch)
2010-09-16 16:13:12 +00:00
sbuf_new_for_sysctl(&sbuf, NULL, 128, req);
Add a new physical memory allocator. However, do not yet connect it to the build. This allocator uses a binary buddy system with a twist. First and foremost, this allocator is required to support the implementation of superpages. As a side effect, it enables a more robust implementation of contigmalloc(9). Moreover, this reimplementation of contigmalloc(9) eliminates the acquisition of Giant by contigmalloc(..., M_NOWAIT, ...). The twist is that this allocator tries to reduce the number of TLB misses incurred by accesses through a direct map to small, UMA-managed objects and page table pages. Roughly speaking, the physical pages that are allocated for such purposes are clustered together in the physical address space. The performance benefits vary. In the most extreme case, a uniprocessor kernel running on an Opteron, I measured an 18% reduction in system time during a buildworld. This allocator does not implement page coloring. The reason is that superpages have much the same effect. The contiguous physical memory allocation necessary for a superpage is inherently colored. Finally, the one caveat is that this allocator does not effectively support prezeroed pages. I hope this is temporary. On i386, this is a slight pessimization. However, on amd64, the beneficial effects of the direct-map optimization outweigh the ill effects. I speculate that this is true in general of machines with a direct map. Approved by: re
2007-06-10 00:49:16 +00:00
for (flind = 0; flind < vm_nfreelists; flind++) {
sbuf_printf(&sbuf, "\nFREE LIST %d:\n"
"\n ORDER (SIZE) | NUMBER"
"\n ", flind);
for (pind = 0; pind < VM_NFREEPOOL; pind++)
sbuf_printf(&sbuf, " | POOL %d", pind);
sbuf_printf(&sbuf, "\n-- ");
for (pind = 0; pind < VM_NFREEPOOL; pind++)
sbuf_printf(&sbuf, "-- -- ");
sbuf_printf(&sbuf, "--\n");
for (oind = VM_NFREEORDER - 1; oind >= 0; oind--) {
Correct some format strings used by sysctls. MFC after: 1 week
2010-10-30 18:00:53 +00:00
sbuf_printf(&sbuf, " %2d (%6dK)", oind,
Add a new physical memory allocator. However, do not yet connect it to the build. This allocator uses a binary buddy system with a twist. First and foremost, this allocator is required to support the implementation of superpages. As a side effect, it enables a more robust implementation of contigmalloc(9). Moreover, this reimplementation of contigmalloc(9) eliminates the acquisition of Giant by contigmalloc(..., M_NOWAIT, ...). The twist is that this allocator tries to reduce the number of TLB misses incurred by accesses through a direct map to small, UMA-managed objects and page table pages. Roughly speaking, the physical pages that are allocated for such purposes are clustered together in the physical address space. The performance benefits vary. In the most extreme case, a uniprocessor kernel running on an Opteron, I measured an 18% reduction in system time during a buildworld. This allocator does not implement page coloring. The reason is that superpages have much the same effect. The contiguous physical memory allocation necessary for a superpage is inherently colored. Finally, the one caveat is that this allocator does not effectively support prezeroed pages. I hope this is temporary. On i386, this is a slight pessimization. However, on amd64, the beneficial effects of the direct-map optimization outweigh the ill effects. I speculate that this is true in general of machines with a direct map. Approved by: re
2007-06-10 00:49:16 +00:00
1 << (PAGE_SHIFT - 10 + oind));
for (pind = 0; pind < VM_NFREEPOOL; pind++) {
fl = vm_phys_free_queues[flind][pind];
Correct some format strings used by sysctls. MFC after: 1 week
2010-10-30 18:00:53 +00:00
sbuf_printf(&sbuf, " | %6d", fl[oind].lcnt);
Add a new physical memory allocator. However, do not yet connect it to the build. This allocator uses a binary buddy system with a twist. First and foremost, this allocator is required to support the implementation of superpages. As a side effect, it enables a more robust implementation of contigmalloc(9). Moreover, this reimplementation of contigmalloc(9) eliminates the acquisition of Giant by contigmalloc(..., M_NOWAIT, ...). The twist is that this allocator tries to reduce the number of TLB misses incurred by accesses through a direct map to small, UMA-managed objects and page table pages. Roughly speaking, the physical pages that are allocated for such purposes are clustered together in the physical address space. The performance benefits vary. In the most extreme case, a uniprocessor kernel running on an Opteron, I measured an 18% reduction in system time during a buildworld. This allocator does not implement page coloring. The reason is that superpages have much the same effect. The contiguous physical memory allocation necessary for a superpage is inherently colored. Finally, the one caveat is that this allocator does not effectively support prezeroed pages. I hope this is temporary. On i386, this is a slight pessimization. However, on amd64, the beneficial effects of the direct-map optimization outweigh the ill effects. I speculate that this is true in general of machines with a direct map. Approved by: re
2007-06-10 00:49:16 +00:00
}
sbuf_printf(&sbuf, "\n");
}
}
Re-add r212370 now that the LOR in powerpc64 has been resolved: Add a drain function for struct sysctl_req, and use it for a variety of handlers, some of which had to do awkward things to get a large enough SBUF_FIXEDLEN buffer. Note that some sysctl handlers were explicitly outputting a trailing NUL byte. This behaviour was preserved, though it should not be necessary. Reviewed by: phk (original patch)
2010-09-16 16:13:12 +00:00
error = sbuf_finish(&sbuf);
Add a new physical memory allocator. However, do not yet connect it to the build. This allocator uses a binary buddy system with a twist. First and foremost, this allocator is required to support the implementation of superpages. As a side effect, it enables a more robust implementation of contigmalloc(9). Moreover, this reimplementation of contigmalloc(9) eliminates the acquisition of Giant by contigmalloc(..., M_NOWAIT, ...). The twist is that this allocator tries to reduce the number of TLB misses incurred by accesses through a direct map to small, UMA-managed objects and page table pages. Roughly speaking, the physical pages that are allocated for such purposes are clustered together in the physical address space. The performance benefits vary. In the most extreme case, a uniprocessor kernel running on an Opteron, I measured an 18% reduction in system time during a buildworld. This allocator does not implement page coloring. The reason is that superpages have much the same effect. The contiguous physical memory allocation necessary for a superpage is inherently colored. Finally, the one caveat is that this allocator does not effectively support prezeroed pages. I hope this is temporary. On i386, this is a slight pessimization. However, on amd64, the beneficial effects of the direct-map optimization outweigh the ill effects. I speculate that this is true in general of machines with a direct map. Approved by: re
2007-06-10 00:49:16 +00:00
sbuf_delete(&sbuf);
return (error);
}
/*
* Outputs the set of physical memory segments.
*/
static int
sysctl_vm_phys_segs(SYSCTL_HANDLER_ARGS)
{
struct sbuf sbuf;
struct vm_phys_seg *seg;
int error, segind;
Explicitly wire the user buffer rather than doing it implicitly in sbuf_new_for_sysctl(9). This allows using an sbuf with a SYSCTL_OUT drain for extremely large amounts of data where the caller knows that appropriate references are held, and sleeping is not an issue. Inspired by: rwatson
2011-01-27 00:34:12 +00:00
error = sysctl_wire_old_buffer(req, 0);
if (error != 0)
return (error);
Re-add r212370 now that the LOR in powerpc64 has been resolved: Add a drain function for struct sysctl_req, and use it for a variety of handlers, some of which had to do awkward things to get a large enough SBUF_FIXEDLEN buffer. Note that some sysctl handlers were explicitly outputting a trailing NUL byte. This behaviour was preserved, though it should not be necessary. Reviewed by: phk (original patch)
2010-09-16 16:13:12 +00:00
sbuf_new_for_sysctl(&sbuf, NULL, 128, req);
Add a new physical memory allocator. However, do not yet connect it to the build. This allocator uses a binary buddy system with a twist. First and foremost, this allocator is required to support the implementation of superpages. As a side effect, it enables a more robust implementation of contigmalloc(9). Moreover, this reimplementation of contigmalloc(9) eliminates the acquisition of Giant by contigmalloc(..., M_NOWAIT, ...). The twist is that this allocator tries to reduce the number of TLB misses incurred by accesses through a direct map to small, UMA-managed objects and page table pages. Roughly speaking, the physical pages that are allocated for such purposes are clustered together in the physical address space. The performance benefits vary. In the most extreme case, a uniprocessor kernel running on an Opteron, I measured an 18% reduction in system time during a buildworld. This allocator does not implement page coloring. The reason is that superpages have much the same effect. The contiguous physical memory allocation necessary for a superpage is inherently colored. Finally, the one caveat is that this allocator does not effectively support prezeroed pages. I hope this is temporary. On i386, this is a slight pessimization. However, on amd64, the beneficial effects of the direct-map optimization outweigh the ill effects. I speculate that this is true in general of machines with a direct map. Approved by: re
2007-06-10 00:49:16 +00:00
for (segind = 0; segind < vm_phys_nsegs; segind++) {
sbuf_printf(&sbuf, "\nSEGMENT %d:\n\n", segind);
seg = &vm_phys_segs[segind];
sbuf_printf(&sbuf, "start: %#jx\n",
(uintmax_t)seg->start);
sbuf_printf(&sbuf, "end: %#jx\n",
(uintmax_t)seg->end);
Very rough first cut at NUMA support for the physical page allocator. For now it uses a very dumb first-touch allocation policy. This will change in the future. - Each architecture indicates the maximum number of supported memory domains via a new VM_NDOMAIN parameter in <machine/vmparam.h>. - Each cpu now has a PCPU_GET(domain) member to indicate the memory domain a CPU belongs to. Domain values are dense and numbered from 0. - When a platform supports multiple domains, the default freelist (VM_FREELIST_DEFAULT) is split up into N freelists, one for each domain. The MD code is required to populate an array of mem_affinity structures. Each entry in the array defines a range of memory (start and end) and a domain for the range. Multiple entries may be present for a single domain. The list is terminated by an entry where all fields are zero. This array of structures is used to split up phys_avail[] regions that fall in VM_FREELIST_DEFAULT into per-domain freelists. - Each memory domain has a separate lookup-array of freelists that is used when fulfulling a physical memory allocation. Right now the per-domain freelists are listed in a round-robin order for each domain. In the future a table such as the ACPI SLIT table may be used to order the per-domain lookup lists based on the penalty for each memory domain relative to a specific domain. The lookup lists may be examined via a new vm.phys.lookup_lists sysctl. - The first-touch policy is implemented by using PCPU_GET(domain) to pick a lookup list when allocating memory. Reviewed by: alc
2010-07-27 20:33:50 +00:00
sbuf_printf(&sbuf, "domain: %d\n", seg->domain);
Add a new physical memory allocator. However, do not yet connect it to the build. This allocator uses a binary buddy system with a twist. First and foremost, this allocator is required to support the implementation of superpages. As a side effect, it enables a more robust implementation of contigmalloc(9). Moreover, this reimplementation of contigmalloc(9) eliminates the acquisition of Giant by contigmalloc(..., M_NOWAIT, ...). The twist is that this allocator tries to reduce the number of TLB misses incurred by accesses through a direct map to small, UMA-managed objects and page table pages. Roughly speaking, the physical pages that are allocated for such purposes are clustered together in the physical address space. The performance benefits vary. In the most extreme case, a uniprocessor kernel running on an Opteron, I measured an 18% reduction in system time during a buildworld. This allocator does not implement page coloring. The reason is that superpages have much the same effect. The contiguous physical memory allocation necessary for a superpage is inherently colored. Finally, the one caveat is that this allocator does not effectively support prezeroed pages. I hope this is temporary. On i386, this is a slight pessimization. However, on amd64, the beneficial effects of the direct-map optimization outweigh the ill effects. I speculate that this is true in general of machines with a direct map. Approved by: re
2007-06-10 00:49:16 +00:00
sbuf_printf(&sbuf, "free list: %p\n", seg->free_queues);
}
Re-add r212370 now that the LOR in powerpc64 has been resolved: Add a drain function for struct sysctl_req, and use it for a variety of handlers, some of which had to do awkward things to get a large enough SBUF_FIXEDLEN buffer. Note that some sysctl handlers were explicitly outputting a trailing NUL byte. This behaviour was preserved, though it should not be necessary. Reviewed by: phk (original patch)
2010-09-16 16:13:12 +00:00
error = sbuf_finish(&sbuf);
Add a new physical memory allocator. However, do not yet connect it to the build. This allocator uses a binary buddy system with a twist. First and foremost, this allocator is required to support the implementation of superpages. As a side effect, it enables a more robust implementation of contigmalloc(9). Moreover, this reimplementation of contigmalloc(9) eliminates the acquisition of Giant by contigmalloc(..., M_NOWAIT, ...). The twist is that this allocator tries to reduce the number of TLB misses incurred by accesses through a direct map to small, UMA-managed objects and page table pages. Roughly speaking, the physical pages that are allocated for such purposes are clustered together in the physical address space. The performance benefits vary. In the most extreme case, a uniprocessor kernel running on an Opteron, I measured an 18% reduction in system time during a buildworld. This allocator does not implement page coloring. The reason is that superpages have much the same effect. The contiguous physical memory allocation necessary for a superpage is inherently colored. Finally, the one caveat is that this allocator does not effectively support prezeroed pages. I hope this is temporary. On i386, this is a slight pessimization. However, on amd64, the beneficial effects of the direct-map optimization outweigh the ill effects. I speculate that this is true in general of machines with a direct map. Approved by: re
2007-06-10 00:49:16 +00:00
sbuf_delete(&sbuf);
return (error);
}
Very rough first cut at NUMA support for the physical page allocator. For now it uses a very dumb first-touch allocation policy. This will change in the future. - Each architecture indicates the maximum number of supported memory domains via a new VM_NDOMAIN parameter in <machine/vmparam.h>. - Each cpu now has a PCPU_GET(domain) member to indicate the memory domain a CPU belongs to. Domain values are dense and numbered from 0. - When a platform supports multiple domains, the default freelist (VM_FREELIST_DEFAULT) is split up into N freelists, one for each domain. The MD code is required to populate an array of mem_affinity structures. Each entry in the array defines a range of memory (start and end) and a domain for the range. Multiple entries may be present for a single domain. The list is terminated by an entry where all fields are zero. This array of structures is used to split up phys_avail[] regions that fall in VM_FREELIST_DEFAULT into per-domain freelists. - Each memory domain has a separate lookup-array of freelists that is used when fulfulling a physical memory allocation. Right now the per-domain freelists are listed in a round-robin order for each domain. In the future a table such as the ACPI SLIT table may be used to order the per-domain lookup lists based on the penalty for each memory domain relative to a specific domain. The lookup lists may be examined via a new vm.phys.lookup_lists sysctl. - The first-touch policy is implemented by using PCPU_GET(domain) to pick a lookup list when allocating memory. Reviewed by: alc
2010-07-27 20:33:50 +00:00
#if VM_NDOMAIN > 1
/*
* Outputs the set of free list lookup lists.
*/
static int
sysctl_vm_phys_lookup_lists(SYSCTL_HANDLER_ARGS)
{
struct sbuf sbuf;
int domain, error, flind, ndomains;
Explicitly wire the user buffer rather than doing it implicitly in sbuf_new_for_sysctl(9). This allows using an sbuf with a SYSCTL_OUT drain for extremely large amounts of data where the caller knows that appropriate references are held, and sleeping is not an issue. Inspired by: rwatson
2011-01-27 00:34:12 +00:00
error = sysctl_wire_old_buffer(req, 0);
if (error != 0)
return (error);
Re-add r212370 now that the LOR in powerpc64 has been resolved: Add a drain function for struct sysctl_req, and use it for a variety of handlers, some of which had to do awkward things to get a large enough SBUF_FIXEDLEN buffer. Note that some sysctl handlers were explicitly outputting a trailing NUL byte. This behaviour was preserved, though it should not be necessary. Reviewed by: phk (original patch)
2010-09-16 16:13:12 +00:00
sbuf_new_for_sysctl(&sbuf, NULL, 128, req);
Explicitly wire the user buffer rather than doing it implicitly in sbuf_new_for_sysctl(9). This allows using an sbuf with a SYSCTL_OUT drain for extremely large amounts of data where the caller knows that appropriate references are held, and sleeping is not an issue. Inspired by: rwatson
2011-01-27 00:34:12 +00:00
ndomains = vm_nfreelists - VM_NFREELIST + 1;
Very rough first cut at NUMA support for the physical page allocator. For now it uses a very dumb first-touch allocation policy. This will change in the future. - Each architecture indicates the maximum number of supported memory domains via a new VM_NDOMAIN parameter in <machine/vmparam.h>. - Each cpu now has a PCPU_GET(domain) member to indicate the memory domain a CPU belongs to. Domain values are dense and numbered from 0. - When a platform supports multiple domains, the default freelist (VM_FREELIST_DEFAULT) is split up into N freelists, one for each domain. The MD code is required to populate an array of mem_affinity structures. Each entry in the array defines a range of memory (start and end) and a domain for the range. Multiple entries may be present for a single domain. The list is terminated by an entry where all fields are zero. This array of structures is used to split up phys_avail[] regions that fall in VM_FREELIST_DEFAULT into per-domain freelists. - Each memory domain has a separate lookup-array of freelists that is used when fulfulling a physical memory allocation. Right now the per-domain freelists are listed in a round-robin order for each domain. In the future a table such as the ACPI SLIT table may be used to order the per-domain lookup lists based on the penalty for each memory domain relative to a specific domain. The lookup lists may be examined via a new vm.phys.lookup_lists sysctl. - The first-touch policy is implemented by using PCPU_GET(domain) to pick a lookup list when allocating memory. Reviewed by: alc
2010-07-27 20:33:50 +00:00
for (domain = 0; domain < ndomains; domain++) {
sbuf_printf(&sbuf, "\nDOMAIN %d:\n\n", domain);
for (flind = 0; flind < vm_nfreelists; flind++)
sbuf_printf(&sbuf, " [%d]:\t%p\n", flind,
vm_phys_lookup_lists[domain][flind]);
}
Re-add r212370 now that the LOR in powerpc64 has been resolved: Add a drain function for struct sysctl_req, and use it for a variety of handlers, some of which had to do awkward things to get a large enough SBUF_FIXEDLEN buffer. Note that some sysctl handlers were explicitly outputting a trailing NUL byte. This behaviour was preserved, though it should not be necessary. Reviewed by: phk (original patch)
2010-09-16 16:13:12 +00:00
error = sbuf_finish(&sbuf);
Very rough first cut at NUMA support for the physical page allocator. For now it uses a very dumb first-touch allocation policy. This will change in the future. - Each architecture indicates the maximum number of supported memory domains via a new VM_NDOMAIN parameter in <machine/vmparam.h>. - Each cpu now has a PCPU_GET(domain) member to indicate the memory domain a CPU belongs to. Domain values are dense and numbered from 0. - When a platform supports multiple domains, the default freelist (VM_FREELIST_DEFAULT) is split up into N freelists, one for each domain. The MD code is required to populate an array of mem_affinity structures. Each entry in the array defines a range of memory (start and end) and a domain for the range. Multiple entries may be present for a single domain. The list is terminated by an entry where all fields are zero. This array of structures is used to split up phys_avail[] regions that fall in VM_FREELIST_DEFAULT into per-domain freelists. - Each memory domain has a separate lookup-array of freelists that is used when fulfulling a physical memory allocation. Right now the per-domain freelists are listed in a round-robin order for each domain. In the future a table such as the ACPI SLIT table may be used to order the per-domain lookup lists based on the penalty for each memory domain relative to a specific domain. The lookup lists may be examined via a new vm.phys.lookup_lists sysctl. - The first-touch policy is implemented by using PCPU_GET(domain) to pick a lookup list when allocating memory. Reviewed by: alc
2010-07-27 20:33:50 +00:00
sbuf_delete(&sbuf);
return (error);
}
#endif
Add a new physical memory allocator. However, do not yet connect it to the build. This allocator uses a binary buddy system with a twist. First and foremost, this allocator is required to support the implementation of superpages. As a side effect, it enables a more robust implementation of contigmalloc(9). Moreover, this reimplementation of contigmalloc(9) eliminates the acquisition of Giant by contigmalloc(..., M_NOWAIT, ...). The twist is that this allocator tries to reduce the number of TLB misses incurred by accesses through a direct map to small, UMA-managed objects and page table pages. Roughly speaking, the physical pages that are allocated for such purposes are clustered together in the physical address space. The performance benefits vary. In the most extreme case, a uniprocessor kernel running on an Opteron, I measured an 18% reduction in system time during a buildworld. This allocator does not implement page coloring. The reason is that superpages have much the same effect. The contiguous physical memory allocation necessary for a superpage is inherently colored. Finally, the one caveat is that this allocator does not effectively support prezeroed pages. I hope this is temporary. On i386, this is a slight pessimization. However, on amd64, the beneficial effects of the direct-map optimization outweigh the ill effects. I speculate that this is true in general of machines with a direct map. Approved by: re
2007-06-10 00:49:16 +00:00
/*
* Create a physical memory segment.
*/
static void
Very rough first cut at NUMA support for the physical page allocator. For now it uses a very dumb first-touch allocation policy. This will change in the future. - Each architecture indicates the maximum number of supported memory domains via a new VM_NDOMAIN parameter in <machine/vmparam.h>. - Each cpu now has a PCPU_GET(domain) member to indicate the memory domain a CPU belongs to. Domain values are dense and numbered from 0. - When a platform supports multiple domains, the default freelist (VM_FREELIST_DEFAULT) is split up into N freelists, one for each domain. The MD code is required to populate an array of mem_affinity structures. Each entry in the array defines a range of memory (start and end) and a domain for the range. Multiple entries may be present for a single domain. The list is terminated by an entry where all fields are zero. This array of structures is used to split up phys_avail[] regions that fall in VM_FREELIST_DEFAULT into per-domain freelists. - Each memory domain has a separate lookup-array of freelists that is used when fulfulling a physical memory allocation. Right now the per-domain freelists are listed in a round-robin order for each domain. In the future a table such as the ACPI SLIT table may be used to order the per-domain lookup lists based on the penalty for each memory domain relative to a specific domain. The lookup lists may be examined via a new vm.phys.lookup_lists sysctl. - The first-touch policy is implemented by using PCPU_GET(domain) to pick a lookup list when allocating memory. Reviewed by: alc
2010-07-27 20:33:50 +00:00
_vm_phys_create_seg(vm_paddr_t start, vm_paddr_t end, int flind, int domain)
Add a new physical memory allocator. However, do not yet connect it to the build. This allocator uses a binary buddy system with a twist. First and foremost, this allocator is required to support the implementation of superpages. As a side effect, it enables a more robust implementation of contigmalloc(9). Moreover, this reimplementation of contigmalloc(9) eliminates the acquisition of Giant by contigmalloc(..., M_NOWAIT, ...). The twist is that this allocator tries to reduce the number of TLB misses incurred by accesses through a direct map to small, UMA-managed objects and page table pages. Roughly speaking, the physical pages that are allocated for such purposes are clustered together in the physical address space. The performance benefits vary. In the most extreme case, a uniprocessor kernel running on an Opteron, I measured an 18% reduction in system time during a buildworld. This allocator does not implement page coloring. The reason is that superpages have much the same effect. The contiguous physical memory allocation necessary for a superpage is inherently colored. Finally, the one caveat is that this allocator does not effectively support prezeroed pages. I hope this is temporary. On i386, this is a slight pessimization. However, on amd64, the beneficial effects of the direct-map optimization outweigh the ill effects. I speculate that this is true in general of machines with a direct map. Approved by: re
2007-06-10 00:49:16 +00:00
{
struct vm_phys_seg *seg;
#ifdef VM_PHYSSEG_SPARSE
Bah, just revert my earlier change entirely. (Missed alc's request to do this earlier.) Requested by: alc
2012-03-19 19:06:40 +00:00
long pages;
Add a new physical memory allocator. However, do not yet connect it to the build. This allocator uses a binary buddy system with a twist. First and foremost, this allocator is required to support the implementation of superpages. As a side effect, it enables a more robust implementation of contigmalloc(9). Moreover, this reimplementation of contigmalloc(9) eliminates the acquisition of Giant by contigmalloc(..., M_NOWAIT, ...). The twist is that this allocator tries to reduce the number of TLB misses incurred by accesses through a direct map to small, UMA-managed objects and page table pages. Roughly speaking, the physical pages that are allocated for such purposes are clustered together in the physical address space. The performance benefits vary. In the most extreme case, a uniprocessor kernel running on an Opteron, I measured an 18% reduction in system time during a buildworld. This allocator does not implement page coloring. The reason is that superpages have much the same effect. The contiguous physical memory allocation necessary for a superpage is inherently colored. Finally, the one caveat is that this allocator does not effectively support prezeroed pages. I hope this is temporary. On i386, this is a slight pessimization. However, on amd64, the beneficial effects of the direct-map optimization outweigh the ill effects. I speculate that this is true in general of machines with a direct map. Approved by: re
2007-06-10 00:49:16 +00:00
int segind;
pages = 0;
for (segind = 0; segind < vm_phys_nsegs; segind++) {
seg = &vm_phys_segs[segind];
pages += atop(seg->end - seg->start);
}
#endif
KASSERT(vm_phys_nsegs < VM_PHYSSEG_MAX,
("vm_phys_create_seg: increase VM_PHYSSEG_MAX"));
seg = &vm_phys_segs[vm_phys_nsegs++];
seg->start = start;
seg->end = end;
Very rough first cut at NUMA support for the physical page allocator. For now it uses a very dumb first-touch allocation policy. This will change in the future. - Each architecture indicates the maximum number of supported memory domains via a new VM_NDOMAIN parameter in <machine/vmparam.h>. - Each cpu now has a PCPU_GET(domain) member to indicate the memory domain a CPU belongs to. Domain values are dense and numbered from 0. - When a platform supports multiple domains, the default freelist (VM_FREELIST_DEFAULT) is split up into N freelists, one for each domain. The MD code is required to populate an array of mem_affinity structures. Each entry in the array defines a range of memory (start and end) and a domain for the range. Multiple entries may be present for a single domain. The list is terminated by an entry where all fields are zero. This array of structures is used to split up phys_avail[] regions that fall in VM_FREELIST_DEFAULT into per-domain freelists. - Each memory domain has a separate lookup-array of freelists that is used when fulfulling a physical memory allocation. Right now the per-domain freelists are listed in a round-robin order for each domain. In the future a table such as the ACPI SLIT table may be used to order the per-domain lookup lists based on the penalty for each memory domain relative to a specific domain. The lookup lists may be examined via a new vm.phys.lookup_lists sysctl. - The first-touch policy is implemented by using PCPU_GET(domain) to pick a lookup list when allocating memory. Reviewed by: alc
2010-07-27 20:33:50 +00:00
seg->domain = domain;
Add a new physical memory allocator. However, do not yet connect it to the build. This allocator uses a binary buddy system with a twist. First and foremost, this allocator is required to support the implementation of superpages. As a side effect, it enables a more robust implementation of contigmalloc(9). Moreover, this reimplementation of contigmalloc(9) eliminates the acquisition of Giant by contigmalloc(..., M_NOWAIT, ...). The twist is that this allocator tries to reduce the number of TLB misses incurred by accesses through a direct map to small, UMA-managed objects and page table pages. Roughly speaking, the physical pages that are allocated for such purposes are clustered together in the physical address space. The performance benefits vary. In the most extreme case, a uniprocessor kernel running on an Opteron, I measured an 18% reduction in system time during a buildworld. This allocator does not implement page coloring. The reason is that superpages have much the same effect. The contiguous physical memory allocation necessary for a superpage is inherently colored. Finally, the one caveat is that this allocator does not effectively support prezeroed pages. I hope this is temporary. On i386, this is a slight pessimization. However, on amd64, the beneficial effects of the direct-map optimization outweigh the ill effects. I speculate that this is true in general of machines with a direct map. Approved by: re
2007-06-10 00:49:16 +00:00
#ifdef VM_PHYSSEG_SPARSE
seg->first_page = &vm_page_array[pages];
#else
seg->first_page = PHYS_TO_VM_PAGE(start);
Very rough first cut at NUMA support for the physical page allocator. For now it uses a very dumb first-touch allocation policy. This will change in the future. - Each architecture indicates the maximum number of supported memory domains via a new VM_NDOMAIN parameter in <machine/vmparam.h>. - Each cpu now has a PCPU_GET(domain) member to indicate the memory domain a CPU belongs to. Domain values are dense and numbered from 0. - When a platform supports multiple domains, the default freelist (VM_FREELIST_DEFAULT) is split up into N freelists, one for each domain. The MD code is required to populate an array of mem_affinity structures. Each entry in the array defines a range of memory (start and end) and a domain for the range. Multiple entries may be present for a single domain. The list is terminated by an entry where all fields are zero. This array of structures is used to split up phys_avail[] regions that fall in VM_FREELIST_DEFAULT into per-domain freelists. - Each memory domain has a separate lookup-array of freelists that is used when fulfulling a physical memory allocation. Right now the per-domain freelists are listed in a round-robin order for each domain. In the future a table such as the ACPI SLIT table may be used to order the per-domain lookup lists based on the penalty for each memory domain relative to a specific domain. The lookup lists may be examined via a new vm.phys.lookup_lists sysctl. - The first-touch policy is implemented by using PCPU_GET(domain) to pick a lookup list when allocating memory. Reviewed by: alc
2010-07-27 20:33:50 +00:00
#endif
#if VM_NDOMAIN > 1
if (flind == VM_FREELIST_DEFAULT && domain != 0) {
flind = VM_NFREELIST + (domain - 1);
if (flind >= vm_nfreelists)
vm_nfreelists = flind + 1;
}
Add a new physical memory allocator. However, do not yet connect it to the build. This allocator uses a binary buddy system with a twist. First and foremost, this allocator is required to support the implementation of superpages. As a side effect, it enables a more robust implementation of contigmalloc(9). Moreover, this reimplementation of contigmalloc(9) eliminates the acquisition of Giant by contigmalloc(..., M_NOWAIT, ...). The twist is that this allocator tries to reduce the number of TLB misses incurred by accesses through a direct map to small, UMA-managed objects and page table pages. Roughly speaking, the physical pages that are allocated for such purposes are clustered together in the physical address space. The performance benefits vary. In the most extreme case, a uniprocessor kernel running on an Opteron, I measured an 18% reduction in system time during a buildworld. This allocator does not implement page coloring. The reason is that superpages have much the same effect. The contiguous physical memory allocation necessary for a superpage is inherently colored. Finally, the one caveat is that this allocator does not effectively support prezeroed pages. I hope this is temporary. On i386, this is a slight pessimization. However, on amd64, the beneficial effects of the direct-map optimization outweigh the ill effects. I speculate that this is true in general of machines with a direct map. Approved by: re
2007-06-10 00:49:16 +00:00
#endif
seg->free_queues = &vm_phys_free_queues[flind];
}
Very rough first cut at NUMA support for the physical page allocator. For now it uses a very dumb first-touch allocation policy. This will change in the future. - Each architecture indicates the maximum number of supported memory domains via a new VM_NDOMAIN parameter in <machine/vmparam.h>. - Each cpu now has a PCPU_GET(domain) member to indicate the memory domain a CPU belongs to. Domain values are dense and numbered from 0. - When a platform supports multiple domains, the default freelist (VM_FREELIST_DEFAULT) is split up into N freelists, one for each domain. The MD code is required to populate an array of mem_affinity structures. Each entry in the array defines a range of memory (start and end) and a domain for the range. Multiple entries may be present for a single domain. The list is terminated by an entry where all fields are zero. This array of structures is used to split up phys_avail[] regions that fall in VM_FREELIST_DEFAULT into per-domain freelists. - Each memory domain has a separate lookup-array of freelists that is used when fulfulling a physical memory allocation. Right now the per-domain freelists are listed in a round-robin order for each domain. In the future a table such as the ACPI SLIT table may be used to order the per-domain lookup lists based on the penalty for each memory domain relative to a specific domain. The lookup lists may be examined via a new vm.phys.lookup_lists sysctl. - The first-touch policy is implemented by using PCPU_GET(domain) to pick a lookup list when allocating memory. Reviewed by: alc
2010-07-27 20:33:50 +00:00
static void
vm_phys_create_seg(vm_paddr_t start, vm_paddr_t end, int flind)
{
int i;
if (mem_affinity == NULL) {
_vm_phys_create_seg(start, end, flind, 0);
return;
}
for (i = 0;; i++) {
if (mem_affinity[i].end == 0)
panic("Reached end of affinity info");
if (mem_affinity[i].end <= start)
continue;
if (mem_affinity[i].start > start)
panic("No affinity info for start %jx",
(uintmax_t)start);
if (mem_affinity[i].end >= end) {
_vm_phys_create_seg(start, end, flind,
mem_affinity[i].domain);
break;
}
_vm_phys_create_seg(start, mem_affinity[i].end, flind,
mem_affinity[i].domain);
start = mem_affinity[i].end;
}
}
Add a new physical memory allocator. However, do not yet connect it to the build. This allocator uses a binary buddy system with a twist. First and foremost, this allocator is required to support the implementation of superpages. As a side effect, it enables a more robust implementation of contigmalloc(9). Moreover, this reimplementation of contigmalloc(9) eliminates the acquisition of Giant by contigmalloc(..., M_NOWAIT, ...). The twist is that this allocator tries to reduce the number of TLB misses incurred by accesses through a direct map to small, UMA-managed objects and page table pages. Roughly speaking, the physical pages that are allocated for such purposes are clustered together in the physical address space. The performance benefits vary. In the most extreme case, a uniprocessor kernel running on an Opteron, I measured an 18% reduction in system time during a buildworld. This allocator does not implement page coloring. The reason is that superpages have much the same effect. The contiguous physical memory allocation necessary for a superpage is inherently colored. Finally, the one caveat is that this allocator does not effectively support prezeroed pages. I hope this is temporary. On i386, this is a slight pessimization. However, on amd64, the beneficial effects of the direct-map optimization outweigh the ill effects. I speculate that this is true in general of machines with a direct map. Approved by: re
2007-06-10 00:49:16 +00:00
/*
* Initialize the physical memory allocator.
*/
void
vm_phys_init(void)
{
struct vm_freelist *fl;
int flind, i, oind, pind;
Very rough first cut at NUMA support for the physical page allocator. For now it uses a very dumb first-touch allocation policy. This will change in the future. - Each architecture indicates the maximum number of supported memory domains via a new VM_NDOMAIN parameter in <machine/vmparam.h>. - Each cpu now has a PCPU_GET(domain) member to indicate the memory domain a CPU belongs to. Domain values are dense and numbered from 0. - When a platform supports multiple domains, the default freelist (VM_FREELIST_DEFAULT) is split up into N freelists, one for each domain. The MD code is required to populate an array of mem_affinity structures. Each entry in the array defines a range of memory (start and end) and a domain for the range. Multiple entries may be present for a single domain. The list is terminated by an entry where all fields are zero. This array of structures is used to split up phys_avail[] regions that fall in VM_FREELIST_DEFAULT into per-domain freelists. - Each memory domain has a separate lookup-array of freelists that is used when fulfulling a physical memory allocation. Right now the per-domain freelists are listed in a round-robin order for each domain. In the future a table such as the ACPI SLIT table may be used to order the per-domain lookup lists based on the penalty for each memory domain relative to a specific domain. The lookup lists may be examined via a new vm.phys.lookup_lists sysctl. - The first-touch policy is implemented by using PCPU_GET(domain) to pick a lookup list when allocating memory. Reviewed by: alc
2010-07-27 20:33:50 +00:00
#if VM_NDOMAIN > 1
int ndomains, j;
#endif
Add a new physical memory allocator. However, do not yet connect it to the build. This allocator uses a binary buddy system with a twist. First and foremost, this allocator is required to support the implementation of superpages. As a side effect, it enables a more robust implementation of contigmalloc(9). Moreover, this reimplementation of contigmalloc(9) eliminates the acquisition of Giant by contigmalloc(..., M_NOWAIT, ...). The twist is that this allocator tries to reduce the number of TLB misses incurred by accesses through a direct map to small, UMA-managed objects and page table pages. Roughly speaking, the physical pages that are allocated for such purposes are clustered together in the physical address space. The performance benefits vary. In the most extreme case, a uniprocessor kernel running on an Opteron, I measured an 18% reduction in system time during a buildworld. This allocator does not implement page coloring. The reason is that superpages have much the same effect. The contiguous physical memory allocation necessary for a superpage is inherently colored. Finally, the one caveat is that this allocator does not effectively support prezeroed pages. I hope this is temporary. On i386, this is a slight pessimization. However, on amd64, the beneficial effects of the direct-map optimization outweigh the ill effects. I speculate that this is true in general of machines with a direct map. Approved by: re
2007-06-10 00:49:16 +00:00
for (i = 0; phys_avail[i + 1] != 0; i += 2) {
#ifdef VM_FREELIST_ISADMA
if (phys_avail[i] < 16777216) {
if (phys_avail[i + 1] > 16777216) {
vm_phys_create_seg(phys_avail[i], 16777216,
VM_FREELIST_ISADMA);
vm_phys_create_seg(16777216, phys_avail[i + 1],
VM_FREELIST_DEFAULT);
} else {
vm_phys_create_seg(phys_avail[i],
phys_avail[i + 1], VM_FREELIST_ISADMA);
}
if (VM_FREELIST_ISADMA >= vm_nfreelists)
vm_nfreelists = VM_FREELIST_ISADMA + 1;
} else
#endif
#ifdef VM_FREELIST_HIGHMEM
if (phys_avail[i + 1] > VM_HIGHMEM_ADDRESS) {
if (phys_avail[i] < VM_HIGHMEM_ADDRESS) {
vm_phys_create_seg(phys_avail[i],
VM_HIGHMEM_ADDRESS, VM_FREELIST_DEFAULT);
vm_phys_create_seg(VM_HIGHMEM_ADDRESS,
phys_avail[i + 1], VM_FREELIST_HIGHMEM);
} else {
vm_phys_create_seg(phys_avail[i],
phys_avail[i + 1], VM_FREELIST_HIGHMEM);
}
if (VM_FREELIST_HIGHMEM >= vm_nfreelists)
vm_nfreelists = VM_FREELIST_HIGHMEM + 1;
} else
#endif
vm_phys_create_seg(phys_avail[i], phys_avail[i + 1],
VM_FREELIST_DEFAULT);
}
for (flind = 0; flind < vm_nfreelists; flind++) {
for (pind = 0; pind < VM_NFREEPOOL; pind++) {
fl = vm_phys_free_queues[flind][pind];
for (oind = 0; oind < VM_NFREEORDER; oind++)
TAILQ_INIT(&fl[oind].pl);
}
}
Very rough first cut at NUMA support for the physical page allocator. For now it uses a very dumb first-touch allocation policy. This will change in the future. - Each architecture indicates the maximum number of supported memory domains via a new VM_NDOMAIN parameter in <machine/vmparam.h>. - Each cpu now has a PCPU_GET(domain) member to indicate the memory domain a CPU belongs to. Domain values are dense and numbered from 0. - When a platform supports multiple domains, the default freelist (VM_FREELIST_DEFAULT) is split up into N freelists, one for each domain. The MD code is required to populate an array of mem_affinity structures. Each entry in the array defines a range of memory (start and end) and a domain for the range. Multiple entries may be present for a single domain. The list is terminated by an entry where all fields are zero. This array of structures is used to split up phys_avail[] regions that fall in VM_FREELIST_DEFAULT into per-domain freelists. - Each memory domain has a separate lookup-array of freelists that is used when fulfulling a physical memory allocation. Right now the per-domain freelists are listed in a round-robin order for each domain. In the future a table such as the ACPI SLIT table may be used to order the per-domain lookup lists based on the penalty for each memory domain relative to a specific domain. The lookup lists may be examined via a new vm.phys.lookup_lists sysctl. - The first-touch policy is implemented by using PCPU_GET(domain) to pick a lookup list when allocating memory. Reviewed by: alc
2010-07-27 20:33:50 +00:00
#if VM_NDOMAIN > 1
/*
* Build a free list lookup list for each domain. All of the
* memory domain lists are inserted at the VM_FREELIST_DEFAULT
* index in a round-robin order starting with the current
* domain.
*/
ndomains = vm_nfreelists - VM_NFREELIST + 1;
for (flind = 0; flind < VM_FREELIST_DEFAULT; flind++)
for (i = 0; i < ndomains; i++)
vm_phys_lookup_lists[i][flind] =
&vm_phys_free_queues[flind];
for (i = 0; i < ndomains; i++)
for (j = 0; j < ndomains; j++) {
flind = (i + j) % ndomains;
if (flind == 0)
flind = VM_FREELIST_DEFAULT;
else
flind += VM_NFREELIST - 1;
vm_phys_lookup_lists[i][VM_FREELIST_DEFAULT + j] =
&vm_phys_free_queues[flind];
}
for (flind = VM_FREELIST_DEFAULT + 1; flind < VM_NFREELIST;
flind++)
for (i = 0; i < ndomains; i++)
vm_phys_lookup_lists[i][flind + ndomains - 1] =
&vm_phys_free_queues[flind];
#else
for (flind = 0; flind < vm_nfreelists; flind++)
vm_phys_lookup_lists[0][flind] = &vm_phys_free_queues[flind];
#endif
Add a new physical memory allocator. However, do not yet connect it to the build. This allocator uses a binary buddy system with a twist. First and foremost, this allocator is required to support the implementation of superpages. As a side effect, it enables a more robust implementation of contigmalloc(9). Moreover, this reimplementation of contigmalloc(9) eliminates the acquisition of Giant by contigmalloc(..., M_NOWAIT, ...). The twist is that this allocator tries to reduce the number of TLB misses incurred by accesses through a direct map to small, UMA-managed objects and page table pages. Roughly speaking, the physical pages that are allocated for such purposes are clustered together in the physical address space. The performance benefits vary. In the most extreme case, a uniprocessor kernel running on an Opteron, I measured an 18% reduction in system time during a buildworld. This allocator does not implement page coloring. The reason is that superpages have much the same effect. The contiguous physical memory allocation necessary for a superpage is inherently colored. Finally, the one caveat is that this allocator does not effectively support prezeroed pages. I hope this is temporary. On i386, this is a slight pessimization. However, on amd64, the beneficial effects of the direct-map optimization outweigh the ill effects. I speculate that this is true in general of machines with a direct map. Approved by: re
2007-06-10 00:49:16 +00:00
}
/*
* Split a contiguous, power of two-sized set of physical pages.
*/
static __inline void
vm_phys_split_pages(vm_page_t m, int oind, struct vm_freelist *fl, int order)
{
vm_page_t m_buddy;
while (oind > order) {
oind--;
m_buddy = &m[1 << oind];
KASSERT(m_buddy->order == VM_NFREEORDER,
("vm_phys_split_pages: page %p has unexpected order %d",
m_buddy, m_buddy->order));
m_buddy->order = oind;
TAILQ_INSERT_HEAD(&fl[oind].pl, m_buddy, pageq);
fl[oind].lcnt++;
}
}
/*
* Initialize a physical page and add it to the free lists.
*/
void
vm_phys_add_page(vm_paddr_t pa)
{
vm_page_t m;
cnt.v_page_count++;
m = vm_phys_paddr_to_vm_page(pa);
m->phys_addr = pa;
Explicitly initialize the page's queue field to PQ_NONE instead of relying on PQ_NONE being zero. Redefine PQ_NONE and PQ_COUNT so that a page queue isn't allocated for PQ_NONE. Reviewed by: kib@
2011-01-17 19:17:26 +00:00
m->queue = PQ_NONE;
Add a new physical memory allocator. However, do not yet connect it to the build. This allocator uses a binary buddy system with a twist. First and foremost, this allocator is required to support the implementation of superpages. As a side effect, it enables a more robust implementation of contigmalloc(9). Moreover, this reimplementation of contigmalloc(9) eliminates the acquisition of Giant by contigmalloc(..., M_NOWAIT, ...). The twist is that this allocator tries to reduce the number of TLB misses incurred by accesses through a direct map to small, UMA-managed objects and page table pages. Roughly speaking, the physical pages that are allocated for such purposes are clustered together in the physical address space. The performance benefits vary. In the most extreme case, a uniprocessor kernel running on an Opteron, I measured an 18% reduction in system time during a buildworld. This allocator does not implement page coloring. The reason is that superpages have much the same effect. The contiguous physical memory allocation necessary for a superpage is inherently colored. Finally, the one caveat is that this allocator does not effectively support prezeroed pages. I hope this is temporary. On i386, this is a slight pessimization. However, on amd64, the beneficial effects of the direct-map optimization outweigh the ill effects. I speculate that this is true in general of machines with a direct map. Approved by: re
2007-06-10 00:49:16 +00:00
m->segind = vm_phys_paddr_to_segind(pa);
m->flags = PG_FREE;
KASSERT(m->order == VM_NFREEORDER,
("vm_phys_add_page: page %p has unexpected order %d",
m, m->order));
m->pool = VM_FREEPOOL_DEFAULT;
pmap_page_init(m);
mtx_lock(&vm_page_queue_free_mtx);
Change the management of cached pages (PQ_CACHE) in two fundamental ways: (1) Cached pages are no longer kept in the object's resident page splay tree and memq. Instead, they are kept in a separate per-object splay tree of cached pages. However, access to this new per-object splay tree is synchronized by the _free_ page queues lock, not to be confused with the heavily contended page queues lock. Consequently, a cached page can be reclaimed by vm_page_alloc(9) without acquiring the object's lock or the page queues lock. This solves a problem independently reported by tegge@ and Isilon. Specifically, they observed the page daemon consuming a great deal of CPU time because of pages bouncing back and forth between the cache queue (PQ_CACHE) and the inactive queue (PQ_INACTIVE). The source of this problem turned out to be a deadlock avoidance strategy employed when selecting a cached page to reclaim in vm_page_select_cache(). However, the root cause was really that reclaiming a cached page required the acquisition of an object lock while the page queues lock was already held. Thus, this change addresses the problem at its root, by eliminating the need to acquire the object's lock. Moreover, keeping cached pages in the object's primary splay tree and memq was, in effect, optimizing for the uncommon case. Cached pages are reclaimed far, far more often than they are reactivated. Instead, this change makes reclamation cheaper, especially in terms of synchronization overhead, and reactivation more expensive, because reactivated pages will have to be reentered into the object's primary splay tree and memq. (2) Cached pages are now stored alongside free pages in the physical memory allocator's buddy queues, increasing the likelihood that large allocations of contiguous physical memory (i.e., superpages) will succeed. Finally, as a result of this change long-standing restrictions on when and where a cached page can be reclaimed and returned by vm_page_alloc(9) are eliminated. Specifically, calls to vm_page_alloc(9) specifying VM_ALLOC_INTERRUPT can now reclaim and return a formerly cached page. Consequently, a call to malloc(9) specifying M_NOWAIT is less likely to fail. Discussed with: many over the course of the summer, including jeff@, Justin Husted @ Isilon, peter@, tegge@ Tested by: an earlier version by kris@ Approved by: re (kensmith)
2007-09-25 06:25:06 +00:00
cnt.v_free_count++;
Eliminate two unused functions: vm_phys_alloc_pages() and vm_phys_free_pages(). Rename vm_phys_alloc_pages_locked() to vm_phys_alloc_pages() and vm_phys_free_pages_locked() to vm_phys_free_pages(). Add comments regarding the need for the free page queues lock to be held by callers to these functions. No functional changes. Approved by: re (hrs)
2007-07-14 21:21:17 +00:00
vm_phys_free_pages(m, 0);
Add a new physical memory allocator. However, do not yet connect it to the build. This allocator uses a binary buddy system with a twist. First and foremost, this allocator is required to support the implementation of superpages. As a side effect, it enables a more robust implementation of contigmalloc(9). Moreover, this reimplementation of contigmalloc(9) eliminates the acquisition of Giant by contigmalloc(..., M_NOWAIT, ...). The twist is that this allocator tries to reduce the number of TLB misses incurred by accesses through a direct map to small, UMA-managed objects and page table pages. Roughly speaking, the physical pages that are allocated for such purposes are clustered together in the physical address space. The performance benefits vary. In the most extreme case, a uniprocessor kernel running on an Opteron, I measured an 18% reduction in system time during a buildworld. This allocator does not implement page coloring. The reason is that superpages have much the same effect. The contiguous physical memory allocation necessary for a superpage is inherently colored. Finally, the one caveat is that this allocator does not effectively support prezeroed pages. I hope this is temporary. On i386, this is a slight pessimization. However, on amd64, the beneficial effects of the direct-map optimization outweigh the ill effects. I speculate that this is true in general of machines with a direct map. Approved by: re
2007-06-10 00:49:16 +00:00
mtx_unlock(&vm_page_queue_free_mtx);
}
/*
* Allocate a contiguous, power of two-sized set of physical pages
* from the free lists.
Eliminate two unused functions: vm_phys_alloc_pages() and vm_phys_free_pages(). Rename vm_phys_alloc_pages_locked() to vm_phys_alloc_pages() and vm_phys_free_pages_locked() to vm_phys_free_pages(). Add comments regarding the need for the free page queues lock to be held by callers to these functions. No functional changes. Approved by: re (hrs)
2007-07-14 21:21:17 +00:00
*
* The free page queues must be locked.
Add a new physical memory allocator. However, do not yet connect it to the build. This allocator uses a binary buddy system with a twist. First and foremost, this allocator is required to support the implementation of superpages. As a side effect, it enables a more robust implementation of contigmalloc(9). Moreover, this reimplementation of contigmalloc(9) eliminates the acquisition of Giant by contigmalloc(..., M_NOWAIT, ...). The twist is that this allocator tries to reduce the number of TLB misses incurred by accesses through a direct map to small, UMA-managed objects and page table pages. Roughly speaking, the physical pages that are allocated for such purposes are clustered together in the physical address space. The performance benefits vary. In the most extreme case, a uniprocessor kernel running on an Opteron, I measured an 18% reduction in system time during a buildworld. This allocator does not implement page coloring. The reason is that superpages have much the same effect. The contiguous physical memory allocation necessary for a superpage is inherently colored. Finally, the one caveat is that this allocator does not effectively support prezeroed pages. I hope this is temporary. On i386, this is a slight pessimization. However, on amd64, the beneficial effects of the direct-map optimization outweigh the ill effects. I speculate that this is true in general of machines with a direct map. Approved by: re
2007-06-10 00:49:16 +00:00
*/
vm_page_t
Eliminate two unused functions: vm_phys_alloc_pages() and vm_phys_free_pages(). Rename vm_phys_alloc_pages_locked() to vm_phys_alloc_pages() and vm_phys_free_pages_locked() to vm_phys_free_pages(). Add comments regarding the need for the free page queues lock to be held by callers to these functions. No functional changes. Approved by: re (hrs)
2007-07-14 21:21:17 +00:00
vm_phys_alloc_pages(int pool, int order)
Add a new physical memory allocator. However, do not yet connect it to the build. This allocator uses a binary buddy system with a twist. First and foremost, this allocator is required to support the implementation of superpages. As a side effect, it enables a more robust implementation of contigmalloc(9). Moreover, this reimplementation of contigmalloc(9) eliminates the acquisition of Giant by contigmalloc(..., M_NOWAIT, ...). The twist is that this allocator tries to reduce the number of TLB misses incurred by accesses through a direct map to small, UMA-managed objects and page table pages. Roughly speaking, the physical pages that are allocated for such purposes are clustered together in the physical address space. The performance benefits vary. In the most extreme case, a uniprocessor kernel running on an Opteron, I measured an 18% reduction in system time during a buildworld. This allocator does not implement page coloring. The reason is that superpages have much the same effect. The contiguous physical memory allocation necessary for a superpage is inherently colored. Finally, the one caveat is that this allocator does not effectively support prezeroed pages. I hope this is temporary. On i386, this is a slight pessimization. However, on amd64, the beneficial effects of the direct-map optimization outweigh the ill effects. I speculate that this is true in general of machines with a direct map. Approved by: re
2007-06-10 00:49:16 +00:00
{
Redo the page table page allocation on MIPS, as suggested by alc@. The UMA zone based allocation is replaced by a scheme that creates a new free page list for the KSEG0 region, and a new function in sys/vm that allocates pages from a specific free page list. This also fixes a race condition introduced by the UMA based page table page allocation code. Dropping the page queue and pmap locks before the call to uma_zfree, and re-acquiring them afterwards will introduce a race condtion(noted by alc@). The changes are : - Revert the earlier changes in MIPS pmap.c that added UMA zone for page table pages. - Add a new freelist VM_FREELIST_HIGHMEM to MIPS vmparam.h for memory that is not directly mapped (in 32bit kernel). Normal page allocations will first try the HIGHMEM freelist and then the default(direct mapped) freelist. - Add a new function 'vm_page_t vm_page_alloc_freelist(int flind, int order, int req)' to vm/vm_page.c to allocate a page from a specified freelist. The MIPS page table pages will be allocated using this function from the freelist containing direct mapped pages. - Move the page initialization code from vm_phys_alloc_contig() to a new function vm_page_alloc_init(), and use this function to initialize pages in vm_page_alloc_freelist() too. - Split the function vm_phys_alloc_pages(int pool, int order) to create vm_phys_alloc_freelist_pages(int flind, int pool, int order), and use this function from both vm_page_alloc_freelist() and vm_phys_alloc_pages(). Reviewed by: alc
2010-07-21 09:27:00 +00:00
vm_page_t m;
int flind;
for (flind = 0; flind < vm_nfreelists; flind++) {
m = vm_phys_alloc_freelist_pages(flind, pool, order);
if (m != NULL)
return (m);
}
return (NULL);
}
/*
* Find and dequeue a free page on the given free list, with the
* specified pool and order
*/
vm_page_t
vm_phys_alloc_freelist_pages(int flind, int pool, int order)
{
Add a new physical memory allocator. However, do not yet connect it to the build. This allocator uses a binary buddy system with a twist. First and foremost, this allocator is required to support the implementation of superpages. As a side effect, it enables a more robust implementation of contigmalloc(9). Moreover, this reimplementation of contigmalloc(9) eliminates the acquisition of Giant by contigmalloc(..., M_NOWAIT, ...). The twist is that this allocator tries to reduce the number of TLB misses incurred by accesses through a direct map to small, UMA-managed objects and page table pages. Roughly speaking, the physical pages that are allocated for such purposes are clustered together in the physical address space. The performance benefits vary. In the most extreme case, a uniprocessor kernel running on an Opteron, I measured an 18% reduction in system time during a buildworld. This allocator does not implement page coloring. The reason is that superpages have much the same effect. The contiguous physical memory allocation necessary for a superpage is inherently colored. Finally, the one caveat is that this allocator does not effectively support prezeroed pages. I hope this is temporary. On i386, this is a slight pessimization. However, on amd64, the beneficial effects of the direct-map optimization outweigh the ill effects. I speculate that this is true in general of machines with a direct map. Approved by: re
2007-06-10 00:49:16 +00:00
struct vm_freelist *fl;
struct vm_freelist *alt;
Very rough first cut at NUMA support for the physical page allocator. For now it uses a very dumb first-touch allocation policy. This will change in the future. - Each architecture indicates the maximum number of supported memory domains via a new VM_NDOMAIN parameter in <machine/vmparam.h>. - Each cpu now has a PCPU_GET(domain) member to indicate the memory domain a CPU belongs to. Domain values are dense and numbered from 0. - When a platform supports multiple domains, the default freelist (VM_FREELIST_DEFAULT) is split up into N freelists, one for each domain. The MD code is required to populate an array of mem_affinity structures. Each entry in the array defines a range of memory (start and end) and a domain for the range. Multiple entries may be present for a single domain. The list is terminated by an entry where all fields are zero. This array of structures is used to split up phys_avail[] regions that fall in VM_FREELIST_DEFAULT into per-domain freelists. - Each memory domain has a separate lookup-array of freelists that is used when fulfulling a physical memory allocation. Right now the per-domain freelists are listed in a round-robin order for each domain. In the future a table such as the ACPI SLIT table may be used to order the per-domain lookup lists based on the penalty for each memory domain relative to a specific domain. The lookup lists may be examined via a new vm.phys.lookup_lists sysctl. - The first-touch policy is implemented by using PCPU_GET(domain) to pick a lookup list when allocating memory. Reviewed by: alc
2010-07-27 20:33:50 +00:00
int domain, oind, pind;
Add a new physical memory allocator. However, do not yet connect it to the build. This allocator uses a binary buddy system with a twist. First and foremost, this allocator is required to support the implementation of superpages. As a side effect, it enables a more robust implementation of contigmalloc(9). Moreover, this reimplementation of contigmalloc(9) eliminates the acquisition of Giant by contigmalloc(..., M_NOWAIT, ...). The twist is that this allocator tries to reduce the number of TLB misses incurred by accesses through a direct map to small, UMA-managed objects and page table pages. Roughly speaking, the physical pages that are allocated for such purposes are clustered together in the physical address space. The performance benefits vary. In the most extreme case, a uniprocessor kernel running on an Opteron, I measured an 18% reduction in system time during a buildworld. This allocator does not implement page coloring. The reason is that superpages have much the same effect. The contiguous physical memory allocation necessary for a superpage is inherently colored. Finally, the one caveat is that this allocator does not effectively support prezeroed pages. I hope this is temporary. On i386, this is a slight pessimization. However, on amd64, the beneficial effects of the direct-map optimization outweigh the ill effects. I speculate that this is true in general of machines with a direct map. Approved by: re
2007-06-10 00:49:16 +00:00
vm_page_t m;
Redo the page table page allocation on MIPS, as suggested by alc@. The UMA zone based allocation is replaced by a scheme that creates a new free page list for the KSEG0 region, and a new function in sys/vm that allocates pages from a specific free page list. This also fixes a race condition introduced by the UMA based page table page allocation code. Dropping the page queue and pmap locks before the call to uma_zfree, and re-acquiring them afterwards will introduce a race condtion(noted by alc@). The changes are : - Revert the earlier changes in MIPS pmap.c that added UMA zone for page table pages. - Add a new freelist VM_FREELIST_HIGHMEM to MIPS vmparam.h for memory that is not directly mapped (in 32bit kernel). Normal page allocations will first try the HIGHMEM freelist and then the default(direct mapped) freelist. - Add a new function 'vm_page_t vm_page_alloc_freelist(int flind, int order, int req)' to vm/vm_page.c to allocate a page from a specified freelist. The MIPS page table pages will be allocated using this function from the freelist containing direct mapped pages. - Move the page initialization code from vm_phys_alloc_contig() to a new function vm_page_alloc_init(), and use this function to initialize pages in vm_page_alloc_freelist() too. - Split the function vm_phys_alloc_pages(int pool, int order) to create vm_phys_alloc_freelist_pages(int flind, int pool, int order), and use this function from both vm_page_alloc_freelist() and vm_phys_alloc_pages(). Reviewed by: alc
2010-07-21 09:27:00 +00:00
KASSERT(flind < VM_NFREELIST,
("vm_phys_alloc_freelist_pages: freelist %d is out of range", flind));
Add a new physical memory allocator. However, do not yet connect it to the build. This allocator uses a binary buddy system with a twist. First and foremost, this allocator is required to support the implementation of superpages. As a side effect, it enables a more robust implementation of contigmalloc(9). Moreover, this reimplementation of contigmalloc(9) eliminates the acquisition of Giant by contigmalloc(..., M_NOWAIT, ...). The twist is that this allocator tries to reduce the number of TLB misses incurred by accesses through a direct map to small, UMA-managed objects and page table pages. Roughly speaking, the physical pages that are allocated for such purposes are clustered together in the physical address space. The performance benefits vary. In the most extreme case, a uniprocessor kernel running on an Opteron, I measured an 18% reduction in system time during a buildworld. This allocator does not implement page coloring. The reason is that superpages have much the same effect. The contiguous physical memory allocation necessary for a superpage is inherently colored. Finally, the one caveat is that this allocator does not effectively support prezeroed pages. I hope this is temporary. On i386, this is a slight pessimization. However, on amd64, the beneficial effects of the direct-map optimization outweigh the ill effects. I speculate that this is true in general of machines with a direct map. Approved by: re
2007-06-10 00:49:16 +00:00
KASSERT(pool < VM_NFREEPOOL,
Redo the page table page allocation on MIPS, as suggested by alc@. The UMA zone based allocation is replaced by a scheme that creates a new free page list for the KSEG0 region, and a new function in sys/vm that allocates pages from a specific free page list. This also fixes a race condition introduced by the UMA based page table page allocation code. Dropping the page queue and pmap locks before the call to uma_zfree, and re-acquiring them afterwards will introduce a race condtion(noted by alc@). The changes are : - Revert the earlier changes in MIPS pmap.c that added UMA zone for page table pages. - Add a new freelist VM_FREELIST_HIGHMEM to MIPS vmparam.h for memory that is not directly mapped (in 32bit kernel). Normal page allocations will first try the HIGHMEM freelist and then the default(direct mapped) freelist. - Add a new function 'vm_page_t vm_page_alloc_freelist(int flind, int order, int req)' to vm/vm_page.c to allocate a page from a specified freelist. The MIPS page table pages will be allocated using this function from the freelist containing direct mapped pages. - Move the page initialization code from vm_phys_alloc_contig() to a new function vm_page_alloc_init(), and use this function to initialize pages in vm_page_alloc_freelist() too. - Split the function vm_phys_alloc_pages(int pool, int order) to create vm_phys_alloc_freelist_pages(int flind, int pool, int order), and use this function from both vm_page_alloc_freelist() and vm_phys_alloc_pages(). Reviewed by: alc
2010-07-21 09:27:00 +00:00
("vm_phys_alloc_freelist_pages: pool %d is out of range", pool));
Add a new physical memory allocator. However, do not yet connect it to the build. This allocator uses a binary buddy system with a twist. First and foremost, this allocator is required to support the implementation of superpages. As a side effect, it enables a more robust implementation of contigmalloc(9). Moreover, this reimplementation of contigmalloc(9) eliminates the acquisition of Giant by contigmalloc(..., M_NOWAIT, ...). The twist is that this allocator tries to reduce the number of TLB misses incurred by accesses through a direct map to small, UMA-managed objects and page table pages. Roughly speaking, the physical pages that are allocated for such purposes are clustered together in the physical address space. The performance benefits vary. In the most extreme case, a uniprocessor kernel running on an Opteron, I measured an 18% reduction in system time during a buildworld. This allocator does not implement page coloring. The reason is that superpages have much the same effect. The contiguous physical memory allocation necessary for a superpage is inherently colored. Finally, the one caveat is that this allocator does not effectively support prezeroed pages. I hope this is temporary. On i386, this is a slight pessimization. However, on amd64, the beneficial effects of the direct-map optimization outweigh the ill effects. I speculate that this is true in general of machines with a direct map. Approved by: re
2007-06-10 00:49:16 +00:00
KASSERT(order < VM_NFREEORDER,
Redo the page table page allocation on MIPS, as suggested by alc@. The UMA zone based allocation is replaced by a scheme that creates a new free page list for the KSEG0 region, and a new function in sys/vm that allocates pages from a specific free page list. This also fixes a race condition introduced by the UMA based page table page allocation code. Dropping the page queue and pmap locks before the call to uma_zfree, and re-acquiring them afterwards will introduce a race condtion(noted by alc@). The changes are : - Revert the earlier changes in MIPS pmap.c that added UMA zone for page table pages. - Add a new freelist VM_FREELIST_HIGHMEM to MIPS vmparam.h for memory that is not directly mapped (in 32bit kernel). Normal page allocations will first try the HIGHMEM freelist and then the default(direct mapped) freelist. - Add a new function 'vm_page_t vm_page_alloc_freelist(int flind, int order, int req)' to vm/vm_page.c to allocate a page from a specified freelist. The MIPS page table pages will be allocated using this function from the freelist containing direct mapped pages. - Move the page initialization code from vm_phys_alloc_contig() to a new function vm_page_alloc_init(), and use this function to initialize pages in vm_page_alloc_freelist() too. - Split the function vm_phys_alloc_pages(int pool, int order) to create vm_phys_alloc_freelist_pages(int flind, int pool, int order), and use this function from both vm_page_alloc_freelist() and vm_phys_alloc_pages(). Reviewed by: alc
2010-07-21 09:27:00 +00:00
("vm_phys_alloc_freelist_pages: order %d is out of range", order));
Very rough first cut at NUMA support for the physical page allocator. For now it uses a very dumb first-touch allocation policy. This will change in the future. - Each architecture indicates the maximum number of supported memory domains via a new VM_NDOMAIN parameter in <machine/vmparam.h>. - Each cpu now has a PCPU_GET(domain) member to indicate the memory domain a CPU belongs to. Domain values are dense and numbered from 0. - When a platform supports multiple domains, the default freelist (VM_FREELIST_DEFAULT) is split up into N freelists, one for each domain. The MD code is required to populate an array of mem_affinity structures. Each entry in the array defines a range of memory (start and end) and a domain for the range. Multiple entries may be present for a single domain. The list is terminated by an entry where all fields are zero. This array of structures is used to split up phys_avail[] regions that fall in VM_FREELIST_DEFAULT into per-domain freelists. - Each memory domain has a separate lookup-array of freelists that is used when fulfulling a physical memory allocation. Right now the per-domain freelists are listed in a round-robin order for each domain. In the future a table such as the ACPI SLIT table may be used to order the per-domain lookup lists based on the penalty for each memory domain relative to a specific domain. The lookup lists may be examined via a new vm.phys.lookup_lists sysctl. - The first-touch policy is implemented by using PCPU_GET(domain) to pick a lookup list when allocating memory. Reviewed by: alc
2010-07-27 20:33:50 +00:00
#if VM_NDOMAIN > 1
domain = PCPU_GET(domain);
#else
domain = 0;
#endif
Add a new physical memory allocator. However, do not yet connect it to the build. This allocator uses a binary buddy system with a twist. First and foremost, this allocator is required to support the implementation of superpages. As a side effect, it enables a more robust implementation of contigmalloc(9). Moreover, this reimplementation of contigmalloc(9) eliminates the acquisition of Giant by contigmalloc(..., M_NOWAIT, ...). The twist is that this allocator tries to reduce the number of TLB misses incurred by accesses through a direct map to small, UMA-managed objects and page table pages. Roughly speaking, the physical pages that are allocated for such purposes are clustered together in the physical address space. The performance benefits vary. In the most extreme case, a uniprocessor kernel running on an Opteron, I measured an 18% reduction in system time during a buildworld. This allocator does not implement page coloring. The reason is that superpages have much the same effect. The contiguous physical memory allocation necessary for a superpage is inherently colored. Finally, the one caveat is that this allocator does not effectively support prezeroed pages. I hope this is temporary. On i386, this is a slight pessimization. However, on amd64, the beneficial effects of the direct-map optimization outweigh the ill effects. I speculate that this is true in general of machines with a direct map. Approved by: re
2007-06-10 00:49:16 +00:00
mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
Very rough first cut at NUMA support for the physical page allocator. For now it uses a very dumb first-touch allocation policy. This will change in the future. - Each architecture indicates the maximum number of supported memory domains via a new VM_NDOMAIN parameter in <machine/vmparam.h>. - Each cpu now has a PCPU_GET(domain) member to indicate the memory domain a CPU belongs to. Domain values are dense and numbered from 0. - When a platform supports multiple domains, the default freelist (VM_FREELIST_DEFAULT) is split up into N freelists, one for each domain. The MD code is required to populate an array of mem_affinity structures. Each entry in the array defines a range of memory (start and end) and a domain for the range. Multiple entries may be present for a single domain. The list is terminated by an entry where all fields are zero. This array of structures is used to split up phys_avail[] regions that fall in VM_FREELIST_DEFAULT into per-domain freelists. - Each memory domain has a separate lookup-array of freelists that is used when fulfulling a physical memory allocation. Right now the per-domain freelists are listed in a round-robin order for each domain. In the future a table such as the ACPI SLIT table may be used to order the per-domain lookup lists based on the penalty for each memory domain relative to a specific domain. The lookup lists may be examined via a new vm.phys.lookup_lists sysctl. - The first-touch policy is implemented by using PCPU_GET(domain) to pick a lookup list when allocating memory. Reviewed by: alc
2010-07-27 20:33:50 +00:00
fl = (*vm_phys_lookup_lists[domain][flind])[pool];
Redo the page table page allocation on MIPS, as suggested by alc@. The UMA zone based allocation is replaced by a scheme that creates a new free page list for the KSEG0 region, and a new function in sys/vm that allocates pages from a specific free page list. This also fixes a race condition introduced by the UMA based page table page allocation code. Dropping the page queue and pmap locks before the call to uma_zfree, and re-acquiring them afterwards will introduce a race condtion(noted by alc@). The changes are : - Revert the earlier changes in MIPS pmap.c that added UMA zone for page table pages. - Add a new freelist VM_FREELIST_HIGHMEM to MIPS vmparam.h for memory that is not directly mapped (in 32bit kernel). Normal page allocations will first try the HIGHMEM freelist and then the default(direct mapped) freelist. - Add a new function 'vm_page_t vm_page_alloc_freelist(int flind, int order, int req)' to vm/vm_page.c to allocate a page from a specified freelist. The MIPS page table pages will be allocated using this function from the freelist containing direct mapped pages. - Move the page initialization code from vm_phys_alloc_contig() to a new function vm_page_alloc_init(), and use this function to initialize pages in vm_page_alloc_freelist() too. - Split the function vm_phys_alloc_pages(int pool, int order) to create vm_phys_alloc_freelist_pages(int flind, int pool, int order), and use this function from both vm_page_alloc_freelist() and vm_phys_alloc_pages(). Reviewed by: alc
2010-07-21 09:27:00 +00:00
for (oind = order; oind < VM_NFREEORDER; oind++) {
m = TAILQ_FIRST(&fl[oind].pl);
if (m != NULL) {
TAILQ_REMOVE(&fl[oind].pl, m, pageq);
fl[oind].lcnt--;
m->order = VM_NFREEORDER;
vm_phys_split_pages(m, oind, fl, order);
return (m);
}
}
/*
* The given pool was empty. Find the largest
* contiguous, power-of-two-sized set of pages in any
* pool. Transfer these pages to the given pool, and
* use them to satisfy the allocation.
*/
for (oind = VM_NFREEORDER - 1; oind >= order; oind--) {
for (pind = 0; pind < VM_NFREEPOOL; pind++) {
Very rough first cut at NUMA support for the physical page allocator. For now it uses a very dumb first-touch allocation policy. This will change in the future. - Each architecture indicates the maximum number of supported memory domains via a new VM_NDOMAIN parameter in <machine/vmparam.h>. - Each cpu now has a PCPU_GET(domain) member to indicate the memory domain a CPU belongs to. Domain values are dense and numbered from 0. - When a platform supports multiple domains, the default freelist (VM_FREELIST_DEFAULT) is split up into N freelists, one for each domain. The MD code is required to populate an array of mem_affinity structures. Each entry in the array defines a range of memory (start and end) and a domain for the range. Multiple entries may be present for a single domain. The list is terminated by an entry where all fields are zero. This array of structures is used to split up phys_avail[] regions that fall in VM_FREELIST_DEFAULT into per-domain freelists. - Each memory domain has a separate lookup-array of freelists that is used when fulfulling a physical memory allocation. Right now the per-domain freelists are listed in a round-robin order for each domain. In the future a table such as the ACPI SLIT table may be used to order the per-domain lookup lists based on the penalty for each memory domain relative to a specific domain. The lookup lists may be examined via a new vm.phys.lookup_lists sysctl. - The first-touch policy is implemented by using PCPU_GET(domain) to pick a lookup list when allocating memory. Reviewed by: alc
2010-07-27 20:33:50 +00:00
alt = (*vm_phys_lookup_lists[domain][flind])[pind];
Redo the page table page allocation on MIPS, as suggested by alc@. The UMA zone based allocation is replaced by a scheme that creates a new free page list for the KSEG0 region, and a new function in sys/vm that allocates pages from a specific free page list. This also fixes a race condition introduced by the UMA based page table page allocation code. Dropping the page queue and pmap locks before the call to uma_zfree, and re-acquiring them afterwards will introduce a race condtion(noted by alc@). The changes are : - Revert the earlier changes in MIPS pmap.c that added UMA zone for page table pages. - Add a new freelist VM_FREELIST_HIGHMEM to MIPS vmparam.h for memory that is not directly mapped (in 32bit kernel). Normal page allocations will first try the HIGHMEM freelist and then the default(direct mapped) freelist. - Add a new function 'vm_page_t vm_page_alloc_freelist(int flind, int order, int req)' to vm/vm_page.c to allocate a page from a specified freelist. The MIPS page table pages will be allocated using this function from the freelist containing direct mapped pages. - Move the page initialization code from vm_phys_alloc_contig() to a new function vm_page_alloc_init(), and use this function to initialize pages in vm_page_alloc_freelist() too. - Split the function vm_phys_alloc_pages(int pool, int order) to create vm_phys_alloc_freelist_pages(int flind, int pool, int order), and use this function from both vm_page_alloc_freelist() and vm_phys_alloc_pages(). Reviewed by: alc
2010-07-21 09:27:00 +00:00
m = TAILQ_FIRST(&alt[oind].pl);
Add a new physical memory allocator. However, do not yet connect it to the build. This allocator uses a binary buddy system with a twist. First and foremost, this allocator is required to support the implementation of superpages. As a side effect, it enables a more robust implementation of contigmalloc(9). Moreover, this reimplementation of contigmalloc(9) eliminates the acquisition of Giant by contigmalloc(..., M_NOWAIT, ...). The twist is that this allocator tries to reduce the number of TLB misses incurred by accesses through a direct map to small, UMA-managed objects and page table pages. Roughly speaking, the physical pages that are allocated for such purposes are clustered together in the physical address space. The performance benefits vary. In the most extreme case, a uniprocessor kernel running on an Opteron, I measured an 18% reduction in system time during a buildworld. This allocator does not implement page coloring. The reason is that superpages have much the same effect. The contiguous physical memory allocation necessary for a superpage is inherently colored. Finally, the one caveat is that this allocator does not effectively support prezeroed pages. I hope this is temporary. On i386, this is a slight pessimization. However, on amd64, the beneficial effects of the direct-map optimization outweigh the ill effects. I speculate that this is true in general of machines with a direct map. Approved by: re
2007-06-10 00:49:16 +00:00
if (m != NULL) {
Redo the page table page allocation on MIPS, as suggested by alc@. The UMA zone based allocation is replaced by a scheme that creates a new free page list for the KSEG0 region, and a new function in sys/vm that allocates pages from a specific free page list. This also fixes a race condition introduced by the UMA based page table page allocation code. Dropping the page queue and pmap locks before the call to uma_zfree, and re-acquiring them afterwards will introduce a race condtion(noted by alc@). The changes are : - Revert the earlier changes in MIPS pmap.c that added UMA zone for page table pages. - Add a new freelist VM_FREELIST_HIGHMEM to MIPS vmparam.h for memory that is not directly mapped (in 32bit kernel). Normal page allocations will first try the HIGHMEM freelist and then the default(direct mapped) freelist. - Add a new function 'vm_page_t vm_page_alloc_freelist(int flind, int order, int req)' to vm/vm_page.c to allocate a page from a specified freelist. The MIPS page table pages will be allocated using this function from the freelist containing direct mapped pages. - Move the page initialization code from vm_phys_alloc_contig() to a new function vm_page_alloc_init(), and use this function to initialize pages in vm_page_alloc_freelist() too. - Split the function vm_phys_alloc_pages(int pool, int order) to create vm_phys_alloc_freelist_pages(int flind, int pool, int order), and use this function from both vm_page_alloc_freelist() and vm_phys_alloc_pages(). Reviewed by: alc
2010-07-21 09:27:00 +00:00
TAILQ_REMOVE(&alt[oind].pl, m, pageq);
alt[oind].lcnt--;
Add a new physical memory allocator. However, do not yet connect it to the build. This allocator uses a binary buddy system with a twist. First and foremost, this allocator is required to support the implementation of superpages. As a side effect, it enables a more robust implementation of contigmalloc(9). Moreover, this reimplementation of contigmalloc(9) eliminates the acquisition of Giant by contigmalloc(..., M_NOWAIT, ...). The twist is that this allocator tries to reduce the number of TLB misses incurred by accesses through a direct map to small, UMA-managed objects and page table pages. Roughly speaking, the physical pages that are allocated for such purposes are clustered together in the physical address space. The performance benefits vary. In the most extreme case, a uniprocessor kernel running on an Opteron, I measured an 18% reduction in system time during a buildworld. This allocator does not implement page coloring. The reason is that superpages have much the same effect. The contiguous physical memory allocation necessary for a superpage is inherently colored. Finally, the one caveat is that this allocator does not effectively support prezeroed pages. I hope this is temporary. On i386, this is a slight pessimization. However, on amd64, the beneficial effects of the direct-map optimization outweigh the ill effects. I speculate that this is true in general of machines with a direct map. Approved by: re
2007-06-10 00:49:16 +00:00
m->order = VM_NFREEORDER;
Redo the page table page allocation on MIPS, as suggested by alc@. The UMA zone based allocation is replaced by a scheme that creates a new free page list for the KSEG0 region, and a new function in sys/vm that allocates pages from a specific free page list. This also fixes a race condition introduced by the UMA based page table page allocation code. Dropping the page queue and pmap locks before the call to uma_zfree, and re-acquiring them afterwards will introduce a race condtion(noted by alc@). The changes are : - Revert the earlier changes in MIPS pmap.c that added UMA zone for page table pages. - Add a new freelist VM_FREELIST_HIGHMEM to MIPS vmparam.h for memory that is not directly mapped (in 32bit kernel). Normal page allocations will first try the HIGHMEM freelist and then the default(direct mapped) freelist. - Add a new function 'vm_page_t vm_page_alloc_freelist(int flind, int order, int req)' to vm/vm_page.c to allocate a page from a specified freelist. The MIPS page table pages will be allocated using this function from the freelist containing direct mapped pages. - Move the page initialization code from vm_phys_alloc_contig() to a new function vm_page_alloc_init(), and use this function to initialize pages in vm_page_alloc_freelist() too. - Split the function vm_phys_alloc_pages(int pool, int order) to create vm_phys_alloc_freelist_pages(int flind, int pool, int order), and use this function from both vm_page_alloc_freelist() and vm_phys_alloc_pages(). Reviewed by: alc
2010-07-21 09:27:00 +00:00
vm_phys_set_pool(pool, m, oind);
Add a new physical memory allocator. However, do not yet connect it to the build. This allocator uses a binary buddy system with a twist. First and foremost, this allocator is required to support the implementation of superpages. As a side effect, it enables a more robust implementation of contigmalloc(9). Moreover, this reimplementation of contigmalloc(9) eliminates the acquisition of Giant by contigmalloc(..., M_NOWAIT, ...). The twist is that this allocator tries to reduce the number of TLB misses incurred by accesses through a direct map to small, UMA-managed objects and page table pages. Roughly speaking, the physical pages that are allocated for such purposes are clustered together in the physical address space. The performance benefits vary. In the most extreme case, a uniprocessor kernel running on an Opteron, I measured an 18% reduction in system time during a buildworld. This allocator does not implement page coloring. The reason is that superpages have much the same effect. The contiguous physical memory allocation necessary for a superpage is inherently colored. Finally, the one caveat is that this allocator does not effectively support prezeroed pages. I hope this is temporary. On i386, this is a slight pessimization. However, on amd64, the beneficial effects of the direct-map optimization outweigh the ill effects. I speculate that this is true in general of machines with a direct map. Approved by: re
2007-06-10 00:49:16 +00:00
vm_phys_split_pages(m, oind, fl, order);
return (m);
}
}
}
return (NULL);
}
/*
* Find the vm_page corresponding to the given physical address.
*/
vm_page_t
vm_phys_paddr_to_vm_page(vm_paddr_t pa)
{
struct vm_phys_seg *seg;
int segind;
for (segind = 0; segind < vm_phys_nsegs; segind++) {
seg = &vm_phys_segs[segind];
if (pa >= seg->start && pa < seg->end)
return (&seg->first_page[atop(pa - seg->start)]);
}
Track the kernel mapping of a physical page by a new entry in vm_page structure. When the page is shared, the kernel mapping becomes a special type of managed page to force the cache off the page mappings. This is needed to avoid stale entries on all ARM VIVT caches, and VIPT caches with cache color issue. Submitted by: Mark Tinguely Reviewed by: alc Tested by: Grzegorz Bernacki, thompsa
2009-06-18 20:42:37 +00:00
return (NULL);
Add a new physical memory allocator. However, do not yet connect it to the build. This allocator uses a binary buddy system with a twist. First and foremost, this allocator is required to support the implementation of superpages. As a side effect, it enables a more robust implementation of contigmalloc(9). Moreover, this reimplementation of contigmalloc(9) eliminates the acquisition of Giant by contigmalloc(..., M_NOWAIT, ...). The twist is that this allocator tries to reduce the number of TLB misses incurred by accesses through a direct map to small, UMA-managed objects and page table pages. Roughly speaking, the physical pages that are allocated for such purposes are clustered together in the physical address space. The performance benefits vary. In the most extreme case, a uniprocessor kernel running on an Opteron, I measured an 18% reduction in system time during a buildworld. This allocator does not implement page coloring. The reason is that superpages have much the same effect. The contiguous physical memory allocation necessary for a superpage is inherently colored. Finally, the one caveat is that this allocator does not effectively support prezeroed pages. I hope this is temporary. On i386, this is a slight pessimization. However, on amd64, the beneficial effects of the direct-map optimization outweigh the ill effects. I speculate that this is true in general of machines with a direct map. Approved by: re
2007-06-10 00:49:16 +00:00
}
/*
* Find the segment containing the given physical address.
*/
static int
vm_phys_paddr_to_segind(vm_paddr_t pa)
{
struct vm_phys_seg *seg;
int segind;
for (segind = 0; segind < vm_phys_nsegs; segind++) {
seg = &vm_phys_segs[segind];
if (pa >= seg->start && pa < seg->end)
return (segind);
}
panic("vm_phys_paddr_to_segind: paddr %#jx is not in any segment" ,
(uintmax_t)pa);
}
/*
* Free a contiguous, power of two-sized set of physical pages.
Eliminate two unused functions: vm_phys_alloc_pages() and vm_phys_free_pages(). Rename vm_phys_alloc_pages_locked() to vm_phys_alloc_pages() and vm_phys_free_pages_locked() to vm_phys_free_pages(). Add comments regarding the need for the free page queues lock to be held by callers to these functions. No functional changes. Approved by: re (hrs)
2007-07-14 21:21:17 +00:00
*
* The free page queues must be locked.
Add a new physical memory allocator. However, do not yet connect it to the build. This allocator uses a binary buddy system with a twist. First and foremost, this allocator is required to support the implementation of superpages. As a side effect, it enables a more robust implementation of contigmalloc(9). Moreover, this reimplementation of contigmalloc(9) eliminates the acquisition of Giant by contigmalloc(..., M_NOWAIT, ...). The twist is that this allocator tries to reduce the number of TLB misses incurred by accesses through a direct map to small, UMA-managed objects and page table pages. Roughly speaking, the physical pages that are allocated for such purposes are clustered together in the physical address space. The performance benefits vary. In the most extreme case, a uniprocessor kernel running on an Opteron, I measured an 18% reduction in system time during a buildworld. This allocator does not implement page coloring. The reason is that superpages have much the same effect. The contiguous physical memory allocation necessary for a superpage is inherently colored. Finally, the one caveat is that this allocator does not effectively support prezeroed pages. I hope this is temporary. On i386, this is a slight pessimization. However, on amd64, the beneficial effects of the direct-map optimization outweigh the ill effects. I speculate that this is true in general of machines with a direct map. Approved by: re
2007-06-10 00:49:16 +00:00
*/
void
vm_phys_free_pages(vm_page_t m, int order)
{
struct vm_freelist *fl;
struct vm_phys_seg *seg;
Eliminate vm_phys_bootstrap_alloc(). It was a failed attempt at eliminating duplicated code in the various pmap implementations. Micro-optimize vm_phys_free_pages(). Introduce vm_phys_free_contig(). It is fast routine for freeing an arbitrary number of physically contiguous pages. In particular, it doesn't require the number of pages to be a power of two. Use "u_long" instead of "unsigned long". Bruce Evans (bde@) has convinced me that the "boundary" parameters to kmem_alloc_contig(), vm_phys_alloc_contig(), and vm_reserv_reclaim_contig() should be of type "vm_paddr_t" and not "u_long". Make this change.
2011-10-30 05:06:14 +00:00
vm_paddr_t pa;
Add a new physical memory allocator. However, do not yet connect it to the build. This allocator uses a binary buddy system with a twist. First and foremost, this allocator is required to support the implementation of superpages. As a side effect, it enables a more robust implementation of contigmalloc(9). Moreover, this reimplementation of contigmalloc(9) eliminates the acquisition of Giant by contigmalloc(..., M_NOWAIT, ...). The twist is that this allocator tries to reduce the number of TLB misses incurred by accesses through a direct map to small, UMA-managed objects and page table pages. Roughly speaking, the physical pages that are allocated for such purposes are clustered together in the physical address space. The performance benefits vary. In the most extreme case, a uniprocessor kernel running on an Opteron, I measured an 18% reduction in system time during a buildworld. This allocator does not implement page coloring. The reason is that superpages have much the same effect. The contiguous physical memory allocation necessary for a superpage is inherently colored. Finally, the one caveat is that this allocator does not effectively support prezeroed pages. I hope this is temporary. On i386, this is a slight pessimization. However, on amd64, the beneficial effects of the direct-map optimization outweigh the ill effects. I speculate that this is true in general of machines with a direct map. Approved by: re
2007-06-10 00:49:16 +00:00
vm_page_t m_buddy;
KASSERT(m->order == VM_NFREEORDER,
Eliminate two unused functions: vm_phys_alloc_pages() and vm_phys_free_pages(). Rename vm_phys_alloc_pages_locked() to vm_phys_alloc_pages() and vm_phys_free_pages_locked() to vm_phys_free_pages(). Add comments regarding the need for the free page queues lock to be held by callers to these functions. No functional changes. Approved by: re (hrs)
2007-07-14 21:21:17 +00:00
("vm_phys_free_pages: page %p has unexpected order %d",
Add a new physical memory allocator. However, do not yet connect it to the build. This allocator uses a binary buddy system with a twist. First and foremost, this allocator is required to support the implementation of superpages. As a side effect, it enables a more robust implementation of contigmalloc(9). Moreover, this reimplementation of contigmalloc(9) eliminates the acquisition of Giant by contigmalloc(..., M_NOWAIT, ...). The twist is that this allocator tries to reduce the number of TLB misses incurred by accesses through a direct map to small, UMA-managed objects and page table pages. Roughly speaking, the physical pages that are allocated for such purposes are clustered together in the physical address space. The performance benefits vary. In the most extreme case, a uniprocessor kernel running on an Opteron, I measured an 18% reduction in system time during a buildworld. This allocator does not implement page coloring. The reason is that superpages have much the same effect. The contiguous physical memory allocation necessary for a superpage is inherently colored. Finally, the one caveat is that this allocator does not effectively support prezeroed pages. I hope this is temporary. On i386, this is a slight pessimization. However, on amd64, the beneficial effects of the direct-map optimization outweigh the ill effects. I speculate that this is true in general of machines with a direct map. Approved by: re
2007-06-10 00:49:16 +00:00
m, m->order));
KASSERT(m->pool < VM_NFREEPOOL,
Eliminate two unused functions: vm_phys_alloc_pages() and vm_phys_free_pages(). Rename vm_phys_alloc_pages_locked() to vm_phys_alloc_pages() and vm_phys_free_pages_locked() to vm_phys_free_pages(). Add comments regarding the need for the free page queues lock to be held by callers to these functions. No functional changes. Approved by: re (hrs)
2007-07-14 21:21:17 +00:00
("vm_phys_free_pages: page %p has unexpected pool %d",
Add a new physical memory allocator. However, do not yet connect it to the build. This allocator uses a binary buddy system with a twist. First and foremost, this allocator is required to support the implementation of superpages. As a side effect, it enables a more robust implementation of contigmalloc(9). Moreover, this reimplementation of contigmalloc(9) eliminates the acquisition of Giant by contigmalloc(..., M_NOWAIT, ...). The twist is that this allocator tries to reduce the number of TLB misses incurred by accesses through a direct map to small, UMA-managed objects and page table pages. Roughly speaking, the physical pages that are allocated for such purposes are clustered together in the physical address space. The performance benefits vary. In the most extreme case, a uniprocessor kernel running on an Opteron, I measured an 18% reduction in system time during a buildworld. This allocator does not implement page coloring. The reason is that superpages have much the same effect. The contiguous physical memory allocation necessary for a superpage is inherently colored. Finally, the one caveat is that this allocator does not effectively support prezeroed pages. I hope this is temporary. On i386, this is a slight pessimization. However, on amd64, the beneficial effects of the direct-map optimization outweigh the ill effects. I speculate that this is true in general of machines with a direct map. Approved by: re
2007-06-10 00:49:16 +00:00
m, m->pool));
KASSERT(order < VM_NFREEORDER,
Eliminate two unused functions: vm_phys_alloc_pages() and vm_phys_free_pages(). Rename vm_phys_alloc_pages_locked() to vm_phys_alloc_pages() and vm_phys_free_pages_locked() to vm_phys_free_pages(). Add comments regarding the need for the free page queues lock to be held by callers to these functions. No functional changes. Approved by: re (hrs)
2007-07-14 21:21:17 +00:00
("vm_phys_free_pages: order %d is out of range", order));
Add a new physical memory allocator. However, do not yet connect it to the build. This allocator uses a binary buddy system with a twist. First and foremost, this allocator is required to support the implementation of superpages. As a side effect, it enables a more robust implementation of contigmalloc(9). Moreover, this reimplementation of contigmalloc(9) eliminates the acquisition of Giant by contigmalloc(..., M_NOWAIT, ...). The twist is that this allocator tries to reduce the number of TLB misses incurred by accesses through a direct map to small, UMA-managed objects and page table pages. Roughly speaking, the physical pages that are allocated for such purposes are clustered together in the physical address space. The performance benefits vary. In the most extreme case, a uniprocessor kernel running on an Opteron, I measured an 18% reduction in system time during a buildworld. This allocator does not implement page coloring. The reason is that superpages have much the same effect. The contiguous physical memory allocation necessary for a superpage is inherently colored. Finally, the one caveat is that this allocator does not effectively support prezeroed pages. I hope this is temporary. On i386, this is a slight pessimization. However, on amd64, the beneficial effects of the direct-map optimization outweigh the ill effects. I speculate that this is true in general of machines with a direct map. Approved by: re
2007-06-10 00:49:16 +00:00
mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
seg = &vm_phys_segs[m->segind];
Eliminate vm_phys_bootstrap_alloc(). It was a failed attempt at eliminating duplicated code in the various pmap implementations. Micro-optimize vm_phys_free_pages(). Introduce vm_phys_free_contig(). It is fast routine for freeing an arbitrary number of physically contiguous pages. In particular, it doesn't require the number of pages to be a power of two. Use "u_long" instead of "unsigned long". Bruce Evans (bde@) has convinced me that the "boundary" parameters to kmem_alloc_contig(), vm_phys_alloc_contig(), and vm_reserv_reclaim_contig() should be of type "vm_paddr_t" and not "u_long". Make this change.
2011-10-30 05:06:14 +00:00
if (order < VM_NFREEORDER - 1) {
pa = VM_PAGE_TO_PHYS(m);
do {
pa ^= ((vm_paddr_t)1 << (PAGE_SHIFT + order));
if (pa < seg->start || pa >= seg->end)
break;
m_buddy = &seg->first_page[atop(pa - seg->start)];
if (m_buddy->order != order)
break;
fl = (*seg->free_queues)[m_buddy->pool];
TAILQ_REMOVE(&fl[order].pl, m_buddy, pageq);
fl[order].lcnt--;
m_buddy->order = VM_NFREEORDER;
if (m_buddy->pool != m->pool)
vm_phys_set_pool(m->pool, m_buddy, order);
order++;
pa &= ~(((vm_paddr_t)1 << (PAGE_SHIFT + order)) - 1);
m = &seg->first_page[atop(pa - seg->start)];
} while (order < VM_NFREEORDER - 1);
Add a new physical memory allocator. However, do not yet connect it to the build. This allocator uses a binary buddy system with a twist. First and foremost, this allocator is required to support the implementation of superpages. As a side effect, it enables a more robust implementation of contigmalloc(9). Moreover, this reimplementation of contigmalloc(9) eliminates the acquisition of Giant by contigmalloc(..., M_NOWAIT, ...). The twist is that this allocator tries to reduce the number of TLB misses incurred by accesses through a direct map to small, UMA-managed objects and page table pages. Roughly speaking, the physical pages that are allocated for such purposes are clustered together in the physical address space. The performance benefits vary. In the most extreme case, a uniprocessor kernel running on an Opteron, I measured an 18% reduction in system time during a buildworld. This allocator does not implement page coloring. The reason is that superpages have much the same effect. The contiguous physical memory allocation necessary for a superpage is inherently colored. Finally, the one caveat is that this allocator does not effectively support prezeroed pages. I hope this is temporary. On i386, this is a slight pessimization. However, on amd64, the beneficial effects of the direct-map optimization outweigh the ill effects. I speculate that this is true in general of machines with a direct map. Approved by: re
2007-06-10 00:49:16 +00:00
}
m->order = order;
fl = (*seg->free_queues)[m->pool];
TAILQ_INSERT_TAIL(&fl[order].pl, m, pageq);
fl[order].lcnt++;
}
Eliminate vm_phys_bootstrap_alloc(). It was a failed attempt at eliminating duplicated code in the various pmap implementations. Micro-optimize vm_phys_free_pages(). Introduce vm_phys_free_contig(). It is fast routine for freeing an arbitrary number of physically contiguous pages. In particular, it doesn't require the number of pages to be a power of two. Use "u_long" instead of "unsigned long". Bruce Evans (bde@) has convinced me that the "boundary" parameters to kmem_alloc_contig(), vm_phys_alloc_contig(), and vm_reserv_reclaim_contig() should be of type "vm_paddr_t" and not "u_long". Make this change.
2011-10-30 05:06:14 +00:00
/*
* Free a contiguous, arbitrarily sized set of physical pages.
*
* The free page queues must be locked.
*/
void
vm_phys_free_contig(vm_page_t m, u_long npages)
{
u_int n;
int order;
/*
* Avoid unnecessary coalescing by freeing the pages in the largest
* possible power-of-two-sized subsets.
*/
mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
for (;; npages -= n) {
/*
* Unsigned "min" is used here so that "order" is assigned
* "VM_NFREEORDER - 1" when "m"'s physical address is zero
* or the low-order bits of its physical address are zero
* because the size of a physical address exceeds the size of
* a long.
*/
order = min(ffsl(VM_PAGE_TO_PHYS(m) >> PAGE_SHIFT) - 1,
VM_NFREEORDER - 1);
n = 1 << order;
if (npages < n)
break;
vm_phys_free_pages(m, order);
m += n;
}
/* The residual "npages" is less than "1 << (VM_NFREEORDER - 1)". */
for (; npages > 0; npages -= n) {
order = flsl(npages) - 1;
n = 1 << order;
vm_phys_free_pages(m, order);
m += n;
}
}
Add a new physical memory allocator. However, do not yet connect it to the build. This allocator uses a binary buddy system with a twist. First and foremost, this allocator is required to support the implementation of superpages. As a side effect, it enables a more robust implementation of contigmalloc(9). Moreover, this reimplementation of contigmalloc(9) eliminates the acquisition of Giant by contigmalloc(..., M_NOWAIT, ...). The twist is that this allocator tries to reduce the number of TLB misses incurred by accesses through a direct map to small, UMA-managed objects and page table pages. Roughly speaking, the physical pages that are allocated for such purposes are clustered together in the physical address space. The performance benefits vary. In the most extreme case, a uniprocessor kernel running on an Opteron, I measured an 18% reduction in system time during a buildworld. This allocator does not implement page coloring. The reason is that superpages have much the same effect. The contiguous physical memory allocation necessary for a superpage is inherently colored. Finally, the one caveat is that this allocator does not effectively support prezeroed pages. I hope this is temporary. On i386, this is a slight pessimization. However, on amd64, the beneficial effects of the direct-map optimization outweigh the ill effects. I speculate that this is true in general of machines with a direct map. Approved by: re
2007-06-10 00:49:16 +00:00
/*
* Set the pool for a contiguous, power of two-sized set of physical pages.
*/
Change the management of cached pages (PQ_CACHE) in two fundamental ways: (1) Cached pages are no longer kept in the object's resident page splay tree and memq. Instead, they are kept in a separate per-object splay tree of cached pages. However, access to this new per-object splay tree is synchronized by the _free_ page queues lock, not to be confused with the heavily contended page queues lock. Consequently, a cached page can be reclaimed by vm_page_alloc(9) without acquiring the object's lock or the page queues lock. This solves a problem independently reported by tegge@ and Isilon. Specifically, they observed the page daemon consuming a great deal of CPU time because of pages bouncing back and forth between the cache queue (PQ_CACHE) and the inactive queue (PQ_INACTIVE). The source of this problem turned out to be a deadlock avoidance strategy employed when selecting a cached page to reclaim in vm_page_select_cache(). However, the root cause was really that reclaiming a cached page required the acquisition of an object lock while the page queues lock was already held. Thus, this change addresses the problem at its root, by eliminating the need to acquire the object's lock. Moreover, keeping cached pages in the object's primary splay tree and memq was, in effect, optimizing for the uncommon case. Cached pages are reclaimed far, far more often than they are reactivated. Instead, this change makes reclamation cheaper, especially in terms of synchronization overhead, and reactivation more expensive, because reactivated pages will have to be reentered into the object's primary splay tree and memq. (2) Cached pages are now stored alongside free pages in the physical memory allocator's buddy queues, increasing the likelihood that large allocations of contiguous physical memory (i.e., superpages) will succeed. Finally, as a result of this change long-standing restrictions on when and where a cached page can be reclaimed and returned by vm_page_alloc(9) are eliminated. Specifically, calls to vm_page_alloc(9) specifying VM_ALLOC_INTERRUPT can now reclaim and return a formerly cached page. Consequently, a call to malloc(9) specifying M_NOWAIT is less likely to fail. Discussed with: many over the course of the summer, including jeff@, Justin Husted @ Isilon, peter@, tegge@ Tested by: an earlier version by kris@ Approved by: re (kensmith)
2007-09-25 06:25:06 +00:00
void
Add a new physical memory allocator. However, do not yet connect it to the build. This allocator uses a binary buddy system with a twist. First and foremost, this allocator is required to support the implementation of superpages. As a side effect, it enables a more robust implementation of contigmalloc(9). Moreover, this reimplementation of contigmalloc(9) eliminates the acquisition of Giant by contigmalloc(..., M_NOWAIT, ...). The twist is that this allocator tries to reduce the number of TLB misses incurred by accesses through a direct map to small, UMA-managed objects and page table pages. Roughly speaking, the physical pages that are allocated for such purposes are clustered together in the physical address space. The performance benefits vary. In the most extreme case, a uniprocessor kernel running on an Opteron, I measured an 18% reduction in system time during a buildworld. This allocator does not implement page coloring. The reason is that superpages have much the same effect. The contiguous physical memory allocation necessary for a superpage is inherently colored. Finally, the one caveat is that this allocator does not effectively support prezeroed pages. I hope this is temporary. On i386, this is a slight pessimization. However, on amd64, the beneficial effects of the direct-map optimization outweigh the ill effects. I speculate that this is true in general of machines with a direct map. Approved by: re
2007-06-10 00:49:16 +00:00
vm_phys_set_pool(int pool, vm_page_t m, int order)
{
vm_page_t m_tmp;
for (m_tmp = m; m_tmp < &m[1 << order]; m_tmp++)
m_tmp->pool = pool;
}
/*
Update the comment describing vm_phys_unfree_page().
2007-12-21 02:44:31 +00:00
* Search for the given physical page "m" in the free lists. If the search
* succeeds, remove "m" from the free lists and return TRUE. Otherwise, return
* FALSE, indicating that "m" is not in the free lists.
Change the management of cached pages (PQ_CACHE) in two fundamental ways: (1) Cached pages are no longer kept in the object's resident page splay tree and memq. Instead, they are kept in a separate per-object splay tree of cached pages. However, access to this new per-object splay tree is synchronized by the _free_ page queues lock, not to be confused with the heavily contended page queues lock. Consequently, a cached page can be reclaimed by vm_page_alloc(9) without acquiring the object's lock or the page queues lock. This solves a problem independently reported by tegge@ and Isilon. Specifically, they observed the page daemon consuming a great deal of CPU time because of pages bouncing back and forth between the cache queue (PQ_CACHE) and the inactive queue (PQ_INACTIVE). The source of this problem turned out to be a deadlock avoidance strategy employed when selecting a cached page to reclaim in vm_page_select_cache(). However, the root cause was really that reclaiming a cached page required the acquisition of an object lock while the page queues lock was already held. Thus, this change addresses the problem at its root, by eliminating the need to acquire the object's lock. Moreover, keeping cached pages in the object's primary splay tree and memq was, in effect, optimizing for the uncommon case. Cached pages are reclaimed far, far more often than they are reactivated. Instead, this change makes reclamation cheaper, especially in terms of synchronization overhead, and reactivation more expensive, because reactivated pages will have to be reentered into the object's primary splay tree and memq. (2) Cached pages are now stored alongside free pages in the physical memory allocator's buddy queues, increasing the likelihood that large allocations of contiguous physical memory (i.e., superpages) will succeed. Finally, as a result of this change long-standing restrictions on when and where a cached page can be reclaimed and returned by vm_page_alloc(9) are eliminated. Specifically, calls to vm_page_alloc(9) specifying VM_ALLOC_INTERRUPT can now reclaim and return a formerly cached page. Consequently, a call to malloc(9) specifying M_NOWAIT is less likely to fail. Discussed with: many over the course of the summer, including jeff@, Justin Husted @ Isilon, peter@, tegge@ Tested by: an earlier version by kris@ Approved by: re (kensmith)
2007-09-25 06:25:06 +00:00
*
* The free page queues must be locked.
*/
Modify vm_phys_unfree_page() so that it no longer requires the given page to be in the free lists. Instead, it now returns TRUE if it removed the page from the free lists and FALSE if the page was not in the free lists. This change is required to support superpage reservations. Specifically, once reservations are introduced, a cached page can either be in the free lists or a reservation.
2007-12-20 22:45:54 +00:00
boolean_t
Change the management of cached pages (PQ_CACHE) in two fundamental ways: (1) Cached pages are no longer kept in the object's resident page splay tree and memq. Instead, they are kept in a separate per-object splay tree of cached pages. However, access to this new per-object splay tree is synchronized by the _free_ page queues lock, not to be confused with the heavily contended page queues lock. Consequently, a cached page can be reclaimed by vm_page_alloc(9) without acquiring the object's lock or the page queues lock. This solves a problem independently reported by tegge@ and Isilon. Specifically, they observed the page daemon consuming a great deal of CPU time because of pages bouncing back and forth between the cache queue (PQ_CACHE) and the inactive queue (PQ_INACTIVE). The source of this problem turned out to be a deadlock avoidance strategy employed when selecting a cached page to reclaim in vm_page_select_cache(). However, the root cause was really that reclaiming a cached page required the acquisition of an object lock while the page queues lock was already held. Thus, this change addresses the problem at its root, by eliminating the need to acquire the object's lock. Moreover, keeping cached pages in the object's primary splay tree and memq was, in effect, optimizing for the uncommon case. Cached pages are reclaimed far, far more often than they are reactivated. Instead, this change makes reclamation cheaper, especially in terms of synchronization overhead, and reactivation more expensive, because reactivated pages will have to be reentered into the object's primary splay tree and memq. (2) Cached pages are now stored alongside free pages in the physical memory allocator's buddy queues, increasing the likelihood that large allocations of contiguous physical memory (i.e., superpages) will succeed. Finally, as a result of this change long-standing restrictions on when and where a cached page can be reclaimed and returned by vm_page_alloc(9) are eliminated. Specifically, calls to vm_page_alloc(9) specifying VM_ALLOC_INTERRUPT can now reclaim and return a formerly cached page. Consequently, a call to malloc(9) specifying M_NOWAIT is less likely to fail. Discussed with: many over the course of the summer, including jeff@, Justin Husted @ Isilon, peter@, tegge@ Tested by: an earlier version by kris@ Approved by: re (kensmith)
2007-09-25 06:25:06 +00:00
vm_phys_unfree_page(vm_page_t m)
{
struct vm_freelist *fl;
struct vm_phys_seg *seg;
vm_paddr_t pa, pa_half;
vm_page_t m_set, m_tmp;
int order;
mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
/*
* First, find the contiguous, power of two-sized set of free
* physical pages containing the given physical page "m" and
* assign it to "m_set".
*/
seg = &vm_phys_segs[m->segind];
for (m_set = m, order = 0; m_set->order == VM_NFREEORDER &&
Correct one half of a loop continuation condition in vm_phys_unfree_page(). At present, this error is inconsequential; the other half of the loop continuation condition is sufficient to achieve correct execution.
2007-12-19 23:09:45 +00:00
order < VM_NFREEORDER - 1; ) {
Change the management of cached pages (PQ_CACHE) in two fundamental ways: (1) Cached pages are no longer kept in the object's resident page splay tree and memq. Instead, they are kept in a separate per-object splay tree of cached pages. However, access to this new per-object splay tree is synchronized by the _free_ page queues lock, not to be confused with the heavily contended page queues lock. Consequently, a cached page can be reclaimed by vm_page_alloc(9) without acquiring the object's lock or the page queues lock. This solves a problem independently reported by tegge@ and Isilon. Specifically, they observed the page daemon consuming a great deal of CPU time because of pages bouncing back and forth between the cache queue (PQ_CACHE) and the inactive queue (PQ_INACTIVE). The source of this problem turned out to be a deadlock avoidance strategy employed when selecting a cached page to reclaim in vm_page_select_cache(). However, the root cause was really that reclaiming a cached page required the acquisition of an object lock while the page queues lock was already held. Thus, this change addresses the problem at its root, by eliminating the need to acquire the object's lock. Moreover, keeping cached pages in the object's primary splay tree and memq was, in effect, optimizing for the uncommon case. Cached pages are reclaimed far, far more often than they are reactivated. Instead, this change makes reclamation cheaper, especially in terms of synchronization overhead, and reactivation more expensive, because reactivated pages will have to be reentered into the object's primary splay tree and memq. (2) Cached pages are now stored alongside free pages in the physical memory allocator's buddy queues, increasing the likelihood that large allocations of contiguous physical memory (i.e., superpages) will succeed. Finally, as a result of this change long-standing restrictions on when and where a cached page can be reclaimed and returned by vm_page_alloc(9) are eliminated. Specifically, calls to vm_page_alloc(9) specifying VM_ALLOC_INTERRUPT can now reclaim and return a formerly cached page. Consequently, a call to malloc(9) specifying M_NOWAIT is less likely to fail. Discussed with: many over the course of the summer, including jeff@, Justin Husted @ Isilon, peter@, tegge@ Tested by: an earlier version by kris@ Approved by: re (kensmith)
2007-09-25 06:25:06 +00:00
order++;
pa = m->phys_addr & (~(vm_paddr_t)0 << (PAGE_SHIFT + order));
Eliminate an unnecessary test from vm_phys_unfree_page().
2008-04-05 05:02:53 +00:00
if (pa >= seg->start)
Modify vm_phys_unfree_page() so that it no longer requires the given page to be in the free lists. Instead, it now returns TRUE if it removed the page from the free lists and FALSE if the page was not in the free lists. This change is required to support superpage reservations. Specifically, once reservations are introduced, a cached page can either be in the free lists or a reservation.
2007-12-20 22:45:54 +00:00
m_set = &seg->first_page[atop(pa - seg->start)];
else
return (FALSE);
Change the management of cached pages (PQ_CACHE) in two fundamental ways: (1) Cached pages are no longer kept in the object's resident page splay tree and memq. Instead, they are kept in a separate per-object splay tree of cached pages. However, access to this new per-object splay tree is synchronized by the _free_ page queues lock, not to be confused with the heavily contended page queues lock. Consequently, a cached page can be reclaimed by vm_page_alloc(9) without acquiring the object's lock or the page queues lock. This solves a problem independently reported by tegge@ and Isilon. Specifically, they observed the page daemon consuming a great deal of CPU time because of pages bouncing back and forth between the cache queue (PQ_CACHE) and the inactive queue (PQ_INACTIVE). The source of this problem turned out to be a deadlock avoidance strategy employed when selecting a cached page to reclaim in vm_page_select_cache(). However, the root cause was really that reclaiming a cached page required the acquisition of an object lock while the page queues lock was already held. Thus, this change addresses the problem at its root, by eliminating the need to acquire the object's lock. Moreover, keeping cached pages in the object's primary splay tree and memq was, in effect, optimizing for the uncommon case. Cached pages are reclaimed far, far more often than they are reactivated. Instead, this change makes reclamation cheaper, especially in terms of synchronization overhead, and reactivation more expensive, because reactivated pages will have to be reentered into the object's primary splay tree and memq. (2) Cached pages are now stored alongside free pages in the physical memory allocator's buddy queues, increasing the likelihood that large allocations of contiguous physical memory (i.e., superpages) will succeed. Finally, as a result of this change long-standing restrictions on when and where a cached page can be reclaimed and returned by vm_page_alloc(9) are eliminated. Specifically, calls to vm_page_alloc(9) specifying VM_ALLOC_INTERRUPT can now reclaim and return a formerly cached page. Consequently, a call to malloc(9) specifying M_NOWAIT is less likely to fail. Discussed with: many over the course of the summer, including jeff@, Justin Husted @ Isilon, peter@, tegge@ Tested by: an earlier version by kris@ Approved by: re (kensmith)
2007-09-25 06:25:06 +00:00
}
Modify vm_phys_unfree_page() so that it no longer requires the given page to be in the free lists. Instead, it now returns TRUE if it removed the page from the free lists and FALSE if the page was not in the free lists. This change is required to support superpage reservations. Specifically, once reservations are introduced, a cached page can either be in the free lists or a reservation.
2007-12-20 22:45:54 +00:00
if (m_set->order < order)
return (FALSE);
if (m_set->order == VM_NFREEORDER)
return (FALSE);
Change the management of cached pages (PQ_CACHE) in two fundamental ways: (1) Cached pages are no longer kept in the object's resident page splay tree and memq. Instead, they are kept in a separate per-object splay tree of cached pages. However, access to this new per-object splay tree is synchronized by the _free_ page queues lock, not to be confused with the heavily contended page queues lock. Consequently, a cached page can be reclaimed by vm_page_alloc(9) without acquiring the object's lock or the page queues lock. This solves a problem independently reported by tegge@ and Isilon. Specifically, they observed the page daemon consuming a great deal of CPU time because of pages bouncing back and forth between the cache queue (PQ_CACHE) and the inactive queue (PQ_INACTIVE). The source of this problem turned out to be a deadlock avoidance strategy employed when selecting a cached page to reclaim in vm_page_select_cache(). However, the root cause was really that reclaiming a cached page required the acquisition of an object lock while the page queues lock was already held. Thus, this change addresses the problem at its root, by eliminating the need to acquire the object's lock. Moreover, keeping cached pages in the object's primary splay tree and memq was, in effect, optimizing for the uncommon case. Cached pages are reclaimed far, far more often than they are reactivated. Instead, this change makes reclamation cheaper, especially in terms of synchronization overhead, and reactivation more expensive, because reactivated pages will have to be reentered into the object's primary splay tree and memq. (2) Cached pages are now stored alongside free pages in the physical memory allocator's buddy queues, increasing the likelihood that large allocations of contiguous physical memory (i.e., superpages) will succeed. Finally, as a result of this change long-standing restrictions on when and where a cached page can be reclaimed and returned by vm_page_alloc(9) are eliminated. Specifically, calls to vm_page_alloc(9) specifying VM_ALLOC_INTERRUPT can now reclaim and return a formerly cached page. Consequently, a call to malloc(9) specifying M_NOWAIT is less likely to fail. Discussed with: many over the course of the summer, including jeff@, Justin Husted @ Isilon, peter@, tegge@ Tested by: an earlier version by kris@ Approved by: re (kensmith)
2007-09-25 06:25:06 +00:00
KASSERT(m_set->order < VM_NFREEORDER,
("vm_phys_unfree_page: page %p has unexpected order %d",
m_set, m_set->order));
/*
* Next, remove "m_set" from the free lists. Finally, extract
* "m" from "m_set" using an iterative algorithm: While "m_set"
* is larger than a page, shrink "m_set" by returning the half
* of "m_set" that does not contain "m" to the free lists.
*/
fl = (*seg->free_queues)[m_set->pool];
order = m_set->order;
TAILQ_REMOVE(&fl[order].pl, m_set, pageq);
fl[order].lcnt--;
m_set->order = VM_NFREEORDER;
while (order > 0) {
order--;
pa_half = m_set->phys_addr ^ (1 << (PAGE_SHIFT + order));
if (m->phys_addr < pa_half)
m_tmp = &seg->first_page[atop(pa_half - seg->start)];
else {
m_tmp = m_set;
m_set = &seg->first_page[atop(pa_half - seg->start)];
}
m_tmp->order = order;
TAILQ_INSERT_HEAD(&fl[order].pl, m_tmp, pageq);
fl[order].lcnt++;
}
KASSERT(m_set == m, ("vm_phys_unfree_page: fatal inconsistency"));
Modify vm_phys_unfree_page() so that it no longer requires the given page to be in the free lists. Instead, it now returns TRUE if it removed the page from the free lists and FALSE if the page was not in the free lists. This change is required to support superpage reservations. Specifically, once reservations are introduced, a cached page can either be in the free lists or a reservation.
2007-12-20 22:45:54 +00:00
return (TRUE);
Change the management of cached pages (PQ_CACHE) in two fundamental ways: (1) Cached pages are no longer kept in the object's resident page splay tree and memq. Instead, they are kept in a separate per-object splay tree of cached pages. However, access to this new per-object splay tree is synchronized by the _free_ page queues lock, not to be confused with the heavily contended page queues lock. Consequently, a cached page can be reclaimed by vm_page_alloc(9) without acquiring the object's lock or the page queues lock. This solves a problem independently reported by tegge@ and Isilon. Specifically, they observed the page daemon consuming a great deal of CPU time because of pages bouncing back and forth between the cache queue (PQ_CACHE) and the inactive queue (PQ_INACTIVE). The source of this problem turned out to be a deadlock avoidance strategy employed when selecting a cached page to reclaim in vm_page_select_cache(). However, the root cause was really that reclaiming a cached page required the acquisition of an object lock while the page queues lock was already held. Thus, this change addresses the problem at its root, by eliminating the need to acquire the object's lock. Moreover, keeping cached pages in the object's primary splay tree and memq was, in effect, optimizing for the uncommon case. Cached pages are reclaimed far, far more often than they are reactivated. Instead, this change makes reclamation cheaper, especially in terms of synchronization overhead, and reactivation more expensive, because reactivated pages will have to be reentered into the object's primary splay tree and memq. (2) Cached pages are now stored alongside free pages in the physical memory allocator's buddy queues, increasing the likelihood that large allocations of contiguous physical memory (i.e., superpages) will succeed. Finally, as a result of this change long-standing restrictions on when and where a cached page can be reclaimed and returned by vm_page_alloc(9) are eliminated. Specifically, calls to vm_page_alloc(9) specifying VM_ALLOC_INTERRUPT can now reclaim and return a formerly cached page. Consequently, a call to malloc(9) specifying M_NOWAIT is less likely to fail. Discussed with: many over the course of the summer, including jeff@, Justin Husted @ Isilon, peter@, tegge@ Tested by: an earlier version by kris@ Approved by: re (kensmith)
2007-09-25 06:25:06 +00:00
}
/*
* Try to zero one physical page. Used by an idle priority thread.
Add a new physical memory allocator. However, do not yet connect it to the build. This allocator uses a binary buddy system with a twist. First and foremost, this allocator is required to support the implementation of superpages. As a side effect, it enables a more robust implementation of contigmalloc(9). Moreover, this reimplementation of contigmalloc(9) eliminates the acquisition of Giant by contigmalloc(..., M_NOWAIT, ...). The twist is that this allocator tries to reduce the number of TLB misses incurred by accesses through a direct map to small, UMA-managed objects and page table pages. Roughly speaking, the physical pages that are allocated for such purposes are clustered together in the physical address space. The performance benefits vary. In the most extreme case, a uniprocessor kernel running on an Opteron, I measured an 18% reduction in system time during a buildworld. This allocator does not implement page coloring. The reason is that superpages have much the same effect. The contiguous physical memory allocation necessary for a superpage is inherently colored. Finally, the one caveat is that this allocator does not effectively support prezeroed pages. I hope this is temporary. On i386, this is a slight pessimization. However, on amd64, the beneficial effects of the direct-map optimization outweigh the ill effects. I speculate that this is true in general of machines with a direct map. Approved by: re
2007-06-10 00:49:16 +00:00
*/
boolean_t
vm_phys_zero_pages_idle(void)
{
Change the management of cached pages (PQ_CACHE) in two fundamental ways: (1) Cached pages are no longer kept in the object's resident page splay tree and memq. Instead, they are kept in a separate per-object splay tree of cached pages. However, access to this new per-object splay tree is synchronized by the _free_ page queues lock, not to be confused with the heavily contended page queues lock. Consequently, a cached page can be reclaimed by vm_page_alloc(9) without acquiring the object's lock or the page queues lock. This solves a problem independently reported by tegge@ and Isilon. Specifically, they observed the page daemon consuming a great deal of CPU time because of pages bouncing back and forth between the cache queue (PQ_CACHE) and the inactive queue (PQ_INACTIVE). The source of this problem turned out to be a deadlock avoidance strategy employed when selecting a cached page to reclaim in vm_page_select_cache(). However, the root cause was really that reclaiming a cached page required the acquisition of an object lock while the page queues lock was already held. Thus, this change addresses the problem at its root, by eliminating the need to acquire the object's lock. Moreover, keeping cached pages in the object's primary splay tree and memq was, in effect, optimizing for the uncommon case. Cached pages are reclaimed far, far more often than they are reactivated. Instead, this change makes reclamation cheaper, especially in terms of synchronization overhead, and reactivation more expensive, because reactivated pages will have to be reentered into the object's primary splay tree and memq. (2) Cached pages are now stored alongside free pages in the physical memory allocator's buddy queues, increasing the likelihood that large allocations of contiguous physical memory (i.e., superpages) will succeed. Finally, as a result of this change long-standing restrictions on when and where a cached page can be reclaimed and returned by vm_page_alloc(9) are eliminated. Specifically, calls to vm_page_alloc(9) specifying VM_ALLOC_INTERRUPT can now reclaim and return a formerly cached page. Consequently, a call to malloc(9) specifying M_NOWAIT is less likely to fail. Discussed with: many over the course of the summer, including jeff@, Justin Husted @ Isilon, peter@, tegge@ Tested by: an earlier version by kris@ Approved by: re (kensmith)
2007-09-25 06:25:06 +00:00
static struct vm_freelist *fl = vm_phys_free_queues[0][0];
static int flind, oind, pind;
Add a new physical memory allocator. However, do not yet connect it to the build. This allocator uses a binary buddy system with a twist. First and foremost, this allocator is required to support the implementation of superpages. As a side effect, it enables a more robust implementation of contigmalloc(9). Moreover, this reimplementation of contigmalloc(9) eliminates the acquisition of Giant by contigmalloc(..., M_NOWAIT, ...). The twist is that this allocator tries to reduce the number of TLB misses incurred by accesses through a direct map to small, UMA-managed objects and page table pages. Roughly speaking, the physical pages that are allocated for such purposes are clustered together in the physical address space. The performance benefits vary. In the most extreme case, a uniprocessor kernel running on an Opteron, I measured an 18% reduction in system time during a buildworld. This allocator does not implement page coloring. The reason is that superpages have much the same effect. The contiguous physical memory allocation necessary for a superpage is inherently colored. Finally, the one caveat is that this allocator does not effectively support prezeroed pages. I hope this is temporary. On i386, this is a slight pessimization. However, on amd64, the beneficial effects of the direct-map optimization outweigh the ill effects. I speculate that this is true in general of machines with a direct map. Approved by: re
2007-06-10 00:49:16 +00:00
vm_page_t m, m_tmp;
mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
Change the management of cached pages (PQ_CACHE) in two fundamental ways: (1) Cached pages are no longer kept in the object's resident page splay tree and memq. Instead, they are kept in a separate per-object splay tree of cached pages. However, access to this new per-object splay tree is synchronized by the _free_ page queues lock, not to be confused with the heavily contended page queues lock. Consequently, a cached page can be reclaimed by vm_page_alloc(9) without acquiring the object's lock or the page queues lock. This solves a problem independently reported by tegge@ and Isilon. Specifically, they observed the page daemon consuming a great deal of CPU time because of pages bouncing back and forth between the cache queue (PQ_CACHE) and the inactive queue (PQ_INACTIVE). The source of this problem turned out to be a deadlock avoidance strategy employed when selecting a cached page to reclaim in vm_page_select_cache(). However, the root cause was really that reclaiming a cached page required the acquisition of an object lock while the page queues lock was already held. Thus, this change addresses the problem at its root, by eliminating the need to acquire the object's lock. Moreover, keeping cached pages in the object's primary splay tree and memq was, in effect, optimizing for the uncommon case. Cached pages are reclaimed far, far more often than they are reactivated. Instead, this change makes reclamation cheaper, especially in terms of synchronization overhead, and reactivation more expensive, because reactivated pages will have to be reentered into the object's primary splay tree and memq. (2) Cached pages are now stored alongside free pages in the physical memory allocator's buddy queues, increasing the likelihood that large allocations of contiguous physical memory (i.e., superpages) will succeed. Finally, as a result of this change long-standing restrictions on when and where a cached page can be reclaimed and returned by vm_page_alloc(9) are eliminated. Specifically, calls to vm_page_alloc(9) specifying VM_ALLOC_INTERRUPT can now reclaim and return a formerly cached page. Consequently, a call to malloc(9) specifying M_NOWAIT is less likely to fail. Discussed with: many over the course of the summer, including jeff@, Justin Husted @ Isilon, peter@, tegge@ Tested by: an earlier version by kris@ Approved by: re (kensmith)
2007-09-25 06:25:06 +00:00
for (;;) {
TAILQ_FOREACH_REVERSE(m, &fl[oind].pl, pglist, pageq) {
for (m_tmp = m; m_tmp < &m[1 << oind]; m_tmp++) {
if ((m_tmp->flags & (PG_CACHED | PG_ZERO)) == 0) {
vm_phys_unfree_page(m_tmp);
cnt.v_free_count--;
mtx_unlock(&vm_page_queue_free_mtx);
pmap_zero_page_idle(m_tmp);
m_tmp->flags |= PG_ZERO;
mtx_lock(&vm_page_queue_free_mtx);
cnt.v_free_count++;
vm_phys_free_pages(m_tmp, 0);
vm_page_zero_count++;
cnt_prezero++;
return (TRUE);
Add a new physical memory allocator. However, do not yet connect it to the build. This allocator uses a binary buddy system with a twist. First and foremost, this allocator is required to support the implementation of superpages. As a side effect, it enables a more robust implementation of contigmalloc(9). Moreover, this reimplementation of contigmalloc(9) eliminates the acquisition of Giant by contigmalloc(..., M_NOWAIT, ...). The twist is that this allocator tries to reduce the number of TLB misses incurred by accesses through a direct map to small, UMA-managed objects and page table pages. Roughly speaking, the physical pages that are allocated for such purposes are clustered together in the physical address space. The performance benefits vary. In the most extreme case, a uniprocessor kernel running on an Opteron, I measured an 18% reduction in system time during a buildworld. This allocator does not implement page coloring. The reason is that superpages have much the same effect. The contiguous physical memory allocation necessary for a superpage is inherently colored. Finally, the one caveat is that this allocator does not effectively support prezeroed pages. I hope this is temporary. On i386, this is a slight pessimization. However, on amd64, the beneficial effects of the direct-map optimization outweigh the ill effects. I speculate that this is true in general of machines with a direct map. Approved by: re
2007-06-10 00:49:16 +00:00
}
}
}
Change the management of cached pages (PQ_CACHE) in two fundamental ways: (1) Cached pages are no longer kept in the object's resident page splay tree and memq. Instead, they are kept in a separate per-object splay tree of cached pages. However, access to this new per-object splay tree is synchronized by the _free_ page queues lock, not to be confused with the heavily contended page queues lock. Consequently, a cached page can be reclaimed by vm_page_alloc(9) without acquiring the object's lock or the page queues lock. This solves a problem independently reported by tegge@ and Isilon. Specifically, they observed the page daemon consuming a great deal of CPU time because of pages bouncing back and forth between the cache queue (PQ_CACHE) and the inactive queue (PQ_INACTIVE). The source of this problem turned out to be a deadlock avoidance strategy employed when selecting a cached page to reclaim in vm_page_select_cache(). However, the root cause was really that reclaiming a cached page required the acquisition of an object lock while the page queues lock was already held. Thus, this change addresses the problem at its root, by eliminating the need to acquire the object's lock. Moreover, keeping cached pages in the object's primary splay tree and memq was, in effect, optimizing for the uncommon case. Cached pages are reclaimed far, far more often than they are reactivated. Instead, this change makes reclamation cheaper, especially in terms of synchronization overhead, and reactivation more expensive, because reactivated pages will have to be reentered into the object's primary splay tree and memq. (2) Cached pages are now stored alongside free pages in the physical memory allocator's buddy queues, increasing the likelihood that large allocations of contiguous physical memory (i.e., superpages) will succeed. Finally, as a result of this change long-standing restrictions on when and where a cached page can be reclaimed and returned by vm_page_alloc(9) are eliminated. Specifically, calls to vm_page_alloc(9) specifying VM_ALLOC_INTERRUPT can now reclaim and return a formerly cached page. Consequently, a call to malloc(9) specifying M_NOWAIT is less likely to fail. Discussed with: many over the course of the summer, including jeff@, Justin Husted @ Isilon, peter@, tegge@ Tested by: an earlier version by kris@ Approved by: re (kensmith)
2007-09-25 06:25:06 +00:00
oind++;
if (oind == VM_NFREEORDER) {
oind = 0;
pind++;
if (pind == VM_NFREEPOOL) {
pind = 0;
flind++;
if (flind == vm_nfreelists)
flind = 0;
}
fl = vm_phys_free_queues[flind][pind];
}
Add a new physical memory allocator. However, do not yet connect it to the build. This allocator uses a binary buddy system with a twist. First and foremost, this allocator is required to support the implementation of superpages. As a side effect, it enables a more robust implementation of contigmalloc(9). Moreover, this reimplementation of contigmalloc(9) eliminates the acquisition of Giant by contigmalloc(..., M_NOWAIT, ...). The twist is that this allocator tries to reduce the number of TLB misses incurred by accesses through a direct map to small, UMA-managed objects and page table pages. Roughly speaking, the physical pages that are allocated for such purposes are clustered together in the physical address space. The performance benefits vary. In the most extreme case, a uniprocessor kernel running on an Opteron, I measured an 18% reduction in system time during a buildworld. This allocator does not implement page coloring. The reason is that superpages have much the same effect. The contiguous physical memory allocation necessary for a superpage is inherently colored. Finally, the one caveat is that this allocator does not effectively support prezeroed pages. I hope this is temporary. On i386, this is a slight pessimization. However, on amd64, the beneficial effects of the direct-map optimization outweigh the ill effects. I speculate that this is true in general of machines with a direct map. Approved by: re
2007-06-10 00:49:16 +00:00
}
}
/*
Update a comment.
2007-06-16 05:25:53 +00:00
* Allocate a contiguous set of physical pages of the given size
* "npages" from the free lists. All of the physical pages must be at
* or above the given physical address "low" and below the given
* physical address "high". The given value "alignment" determines the
* alignment of the first physical page in the set. If the given value
* "boundary" is non-zero, then the set of physical pages cannot cross
* any physical address boundary that is a multiple of that value. Both
Add a new physical memory allocator. However, do not yet connect it to the build. This allocator uses a binary buddy system with a twist. First and foremost, this allocator is required to support the implementation of superpages. As a side effect, it enables a more robust implementation of contigmalloc(9). Moreover, this reimplementation of contigmalloc(9) eliminates the acquisition of Giant by contigmalloc(..., M_NOWAIT, ...). The twist is that this allocator tries to reduce the number of TLB misses incurred by accesses through a direct map to small, UMA-managed objects and page table pages. Roughly speaking, the physical pages that are allocated for such purposes are clustered together in the physical address space. The performance benefits vary. In the most extreme case, a uniprocessor kernel running on an Opteron, I measured an 18% reduction in system time during a buildworld. This allocator does not implement page coloring. The reason is that superpages have much the same effect. The contiguous physical memory allocation necessary for a superpage is inherently colored. Finally, the one caveat is that this allocator does not effectively support prezeroed pages. I hope this is temporary. On i386, this is a slight pessimization. However, on amd64, the beneficial effects of the direct-map optimization outweigh the ill effects. I speculate that this is true in general of machines with a direct map. Approved by: re
2007-06-10 00:49:16 +00:00
* "alignment" and "boundary" must be a power of two.
*/
vm_page_t
Eliminate vm_phys_bootstrap_alloc(). It was a failed attempt at eliminating duplicated code in the various pmap implementations. Micro-optimize vm_phys_free_pages(). Introduce vm_phys_free_contig(). It is fast routine for freeing an arbitrary number of physically contiguous pages. In particular, it doesn't require the number of pages to be a power of two. Use "u_long" instead of "unsigned long". Bruce Evans (bde@) has convinced me that the "boundary" parameters to kmem_alloc_contig(), vm_phys_alloc_contig(), and vm_reserv_reclaim_contig() should be of type "vm_paddr_t" and not "u_long". Make this change.
2011-10-30 05:06:14 +00:00
vm_phys_alloc_contig(u_long npages, vm_paddr_t low, vm_paddr_t high,
u_long alignment, vm_paddr_t boundary)
Add a new physical memory allocator. However, do not yet connect it to the build. This allocator uses a binary buddy system with a twist. First and foremost, this allocator is required to support the implementation of superpages. As a side effect, it enables a more robust implementation of contigmalloc(9). Moreover, this reimplementation of contigmalloc(9) eliminates the acquisition of Giant by contigmalloc(..., M_NOWAIT, ...). The twist is that this allocator tries to reduce the number of TLB misses incurred by accesses through a direct map to small, UMA-managed objects and page table pages. Roughly speaking, the physical pages that are allocated for such purposes are clustered together in the physical address space. The performance benefits vary. In the most extreme case, a uniprocessor kernel running on an Opteron, I measured an 18% reduction in system time during a buildworld. This allocator does not implement page coloring. The reason is that superpages have much the same effect. The contiguous physical memory allocation necessary for a superpage is inherently colored. Finally, the one caveat is that this allocator does not effectively support prezeroed pages. I hope this is temporary. On i386, this is a slight pessimization. However, on amd64, the beneficial effects of the direct-map optimization outweigh the ill effects. I speculate that this is true in general of machines with a direct map. Approved by: re
2007-06-10 00:49:16 +00:00
{
struct vm_freelist *fl;
struct vm_phys_seg *seg;
vm_paddr_t pa, pa_last, size;
Refactor the code that performs physically contiguous memory allocation, yielding a new public interface, vm_page_alloc_contig(). This new function addresses some of the limitations of the current interfaces, contigmalloc() and kmem_alloc_contig(). For example, the physically contiguous memory that is allocated with those interfaces can only be allocated to the kernel vm object and must be mapped into the kernel virtual address space. It also provides functionality that vm_phys_alloc_contig() doesn't, such as wiring the returned pages. Moreover, unlike that function, it respects the low water marks on the paging queues and wakes up the page daemon when necessary. That said, at present, this new function can't be applied to all types of vm objects. However, that restriction will be eliminated in the coming weeks. From a design standpoint, this change also addresses an inconsistency between vm_phys_alloc_contig() and the other vm_phys_alloc*() functions. Specifically, vm_phys_alloc_contig() manipulated vm_page fields that other functions in vm/vm_phys.c didn't. Moreover, vm_phys_alloc_contig() knew about vnodes and reservations. Now, vm_page_alloc_contig() is responsible for these things. Reviewed by: kib Discussed with: jhb
2011-11-16 16:46:09 +00:00
vm_page_t m, m_ret;
Eliminate vm_phys_bootstrap_alloc(). It was a failed attempt at eliminating duplicated code in the various pmap implementations. Micro-optimize vm_phys_free_pages(). Introduce vm_phys_free_contig(). It is fast routine for freeing an arbitrary number of physically contiguous pages. In particular, it doesn't require the number of pages to be a power of two. Use "u_long" instead of "unsigned long". Bruce Evans (bde@) has convinced me that the "boundary" parameters to kmem_alloc_contig(), vm_phys_alloc_contig(), and vm_reserv_reclaim_contig() should be of type "vm_paddr_t" and not "u_long". Make this change.
2011-10-30 05:06:14 +00:00
u_long npages_end;
Refactor the code that performs physically contiguous memory allocation, yielding a new public interface, vm_page_alloc_contig(). This new function addresses some of the limitations of the current interfaces, contigmalloc() and kmem_alloc_contig(). For example, the physically contiguous memory that is allocated with those interfaces can only be allocated to the kernel vm object and must be mapped into the kernel virtual address space. It also provides functionality that vm_phys_alloc_contig() doesn't, such as wiring the returned pages. Moreover, unlike that function, it respects the low water marks on the paging queues and wakes up the page daemon when necessary. That said, at present, this new function can't be applied to all types of vm objects. However, that restriction will be eliminated in the coming weeks. From a design standpoint, this change also addresses an inconsistency between vm_phys_alloc_contig() and the other vm_phys_alloc*() functions. Specifically, vm_phys_alloc_contig() manipulated vm_page fields that other functions in vm/vm_phys.c didn't. Moreover, vm_phys_alloc_contig() knew about vnodes and reservations. Now, vm_page_alloc_contig() is responsible for these things. Reviewed by: kib Discussed with: jhb
2011-11-16 16:46:09 +00:00
int domain, flind, oind, order, pind;
Add a new physical memory allocator. However, do not yet connect it to the build. This allocator uses a binary buddy system with a twist. First and foremost, this allocator is required to support the implementation of superpages. As a side effect, it enables a more robust implementation of contigmalloc(9). Moreover, this reimplementation of contigmalloc(9) eliminates the acquisition of Giant by contigmalloc(..., M_NOWAIT, ...). The twist is that this allocator tries to reduce the number of TLB misses incurred by accesses through a direct map to small, UMA-managed objects and page table pages. Roughly speaking, the physical pages that are allocated for such purposes are clustered together in the physical address space. The performance benefits vary. In the most extreme case, a uniprocessor kernel running on an Opteron, I measured an 18% reduction in system time during a buildworld. This allocator does not implement page coloring. The reason is that superpages have much the same effect. The contiguous physical memory allocation necessary for a superpage is inherently colored. Finally, the one caveat is that this allocator does not effectively support prezeroed pages. I hope this is temporary. On i386, this is a slight pessimization. However, on amd64, the beneficial effects of the direct-map optimization outweigh the ill effects. I speculate that this is true in general of machines with a direct map. Approved by: re
2007-06-10 00:49:16 +00:00
Refactor the code that performs physically contiguous memory allocation, yielding a new public interface, vm_page_alloc_contig(). This new function addresses some of the limitations of the current interfaces, contigmalloc() and kmem_alloc_contig(). For example, the physically contiguous memory that is allocated with those interfaces can only be allocated to the kernel vm object and must be mapped into the kernel virtual address space. It also provides functionality that vm_phys_alloc_contig() doesn't, such as wiring the returned pages. Moreover, unlike that function, it respects the low water marks on the paging queues and wakes up the page daemon when necessary. That said, at present, this new function can't be applied to all types of vm objects. However, that restriction will be eliminated in the coming weeks. From a design standpoint, this change also addresses an inconsistency between vm_phys_alloc_contig() and the other vm_phys_alloc*() functions. Specifically, vm_phys_alloc_contig() manipulated vm_page fields that other functions in vm/vm_phys.c didn't. Moreover, vm_phys_alloc_contig() knew about vnodes and reservations. Now, vm_page_alloc_contig() is responsible for these things. Reviewed by: kib Discussed with: jhb
2011-11-16 16:46:09 +00:00
mtx_assert(&vm_page_queue_free_mtx, MA_OWNED);
Very rough first cut at NUMA support for the physical page allocator. For now it uses a very dumb first-touch allocation policy. This will change in the future. - Each architecture indicates the maximum number of supported memory domains via a new VM_NDOMAIN parameter in <machine/vmparam.h>. - Each cpu now has a PCPU_GET(domain) member to indicate the memory domain a CPU belongs to. Domain values are dense and numbered from 0. - When a platform supports multiple domains, the default freelist (VM_FREELIST_DEFAULT) is split up into N freelists, one for each domain. The MD code is required to populate an array of mem_affinity structures. Each entry in the array defines a range of memory (start and end) and a domain for the range. Multiple entries may be present for a single domain. The list is terminated by an entry where all fields are zero. This array of structures is used to split up phys_avail[] regions that fall in VM_FREELIST_DEFAULT into per-domain freelists. - Each memory domain has a separate lookup-array of freelists that is used when fulfulling a physical memory allocation. Right now the per-domain freelists are listed in a round-robin order for each domain. In the future a table such as the ACPI SLIT table may be used to order the per-domain lookup lists based on the penalty for each memory domain relative to a specific domain. The lookup lists may be examined via a new vm.phys.lookup_lists sysctl. - The first-touch policy is implemented by using PCPU_GET(domain) to pick a lookup list when allocating memory. Reviewed by: alc
2010-07-27 20:33:50 +00:00
#if VM_NDOMAIN > 1
domain = PCPU_GET(domain);
#else
domain = 0;
#endif
Add a new physical memory allocator. However, do not yet connect it to the build. This allocator uses a binary buddy system with a twist. First and foremost, this allocator is required to support the implementation of superpages. As a side effect, it enables a more robust implementation of contigmalloc(9). Moreover, this reimplementation of contigmalloc(9) eliminates the acquisition of Giant by contigmalloc(..., M_NOWAIT, ...). The twist is that this allocator tries to reduce the number of TLB misses incurred by accesses through a direct map to small, UMA-managed objects and page table pages. Roughly speaking, the physical pages that are allocated for such purposes are clustered together in the physical address space. The performance benefits vary. In the most extreme case, a uniprocessor kernel running on an Opteron, I measured an 18% reduction in system time during a buildworld. This allocator does not implement page coloring. The reason is that superpages have much the same effect. The contiguous physical memory allocation necessary for a superpage is inherently colored. Finally, the one caveat is that this allocator does not effectively support prezeroed pages. I hope this is temporary. On i386, this is a slight pessimization. However, on amd64, the beneficial effects of the direct-map optimization outweigh the ill effects. I speculate that this is true in general of machines with a direct map. Approved by: re
2007-06-10 00:49:16 +00:00
size = npages << PAGE_SHIFT;
KASSERT(size != 0,
("vm_phys_alloc_contig: size must not be 0"));
KASSERT((alignment & (alignment - 1)) == 0,
("vm_phys_alloc_contig: alignment must be a power of 2"));
KASSERT((boundary & (boundary - 1)) == 0,
("vm_phys_alloc_contig: boundary must be a power of 2"));
/* Compute the queue that is the best fit for npages. */
for (order = 0; (1 << order) < npages; order++);
for (flind = 0; flind < vm_nfreelists; flind++) {
for (oind = min(order, VM_NFREEORDER - 1); oind < VM_NFREEORDER; oind++) {
for (pind = 0; pind < VM_NFREEPOOL; pind++) {
Very rough first cut at NUMA support for the physical page allocator. For now it uses a very dumb first-touch allocation policy. This will change in the future. - Each architecture indicates the maximum number of supported memory domains via a new VM_NDOMAIN parameter in <machine/vmparam.h>. - Each cpu now has a PCPU_GET(domain) member to indicate the memory domain a CPU belongs to. Domain values are dense and numbered from 0. - When a platform supports multiple domains, the default freelist (VM_FREELIST_DEFAULT) is split up into N freelists, one for each domain. The MD code is required to populate an array of mem_affinity structures. Each entry in the array defines a range of memory (start and end) and a domain for the range. Multiple entries may be present for a single domain. The list is terminated by an entry where all fields are zero. This array of structures is used to split up phys_avail[] regions that fall in VM_FREELIST_DEFAULT into per-domain freelists. - Each memory domain has a separate lookup-array of freelists that is used when fulfulling a physical memory allocation. Right now the per-domain freelists are listed in a round-robin order for each domain. In the future a table such as the ACPI SLIT table may be used to order the per-domain lookup lists based on the penalty for each memory domain relative to a specific domain. The lookup lists may be examined via a new vm.phys.lookup_lists sysctl. - The first-touch policy is implemented by using PCPU_GET(domain) to pick a lookup list when allocating memory. Reviewed by: alc
2010-07-27 20:33:50 +00:00
fl = (*vm_phys_lookup_lists[domain][flind])
[pind];
Add a new physical memory allocator. However, do not yet connect it to the build. This allocator uses a binary buddy system with a twist. First and foremost, this allocator is required to support the implementation of superpages. As a side effect, it enables a more robust implementation of contigmalloc(9). Moreover, this reimplementation of contigmalloc(9) eliminates the acquisition of Giant by contigmalloc(..., M_NOWAIT, ...). The twist is that this allocator tries to reduce the number of TLB misses incurred by accesses through a direct map to small, UMA-managed objects and page table pages. Roughly speaking, the physical pages that are allocated for such purposes are clustered together in the physical address space. The performance benefits vary. In the most extreme case, a uniprocessor kernel running on an Opteron, I measured an 18% reduction in system time during a buildworld. This allocator does not implement page coloring. The reason is that superpages have much the same effect. The contiguous physical memory allocation necessary for a superpage is inherently colored. Finally, the one caveat is that this allocator does not effectively support prezeroed pages. I hope this is temporary. On i386, this is a slight pessimization. However, on amd64, the beneficial effects of the direct-map optimization outweigh the ill effects. I speculate that this is true in general of machines with a direct map. Approved by: re
2007-06-10 00:49:16 +00:00
TAILQ_FOREACH(m_ret, &fl[oind].pl, pageq) {
/*
* A free list may contain physical pages
* from one or more segments.
*/
seg = &vm_phys_segs[m_ret->segind];
if (seg->start > high ||
low >= seg->end)
continue;
/*
* Is the size of this allocation request
* larger than the largest block size?
*/
if (order >= VM_NFREEORDER) {
/*
* Determine if a sufficient number
* of subsequent blocks to satisfy
* the allocation request are free.
*/
pa = VM_PAGE_TO_PHYS(m_ret);
pa_last = pa + size;
for (;;) {
pa += 1 << (PAGE_SHIFT + VM_NFREEORDER - 1);
if (pa >= pa_last)
break;
if (pa < seg->start ||
pa >= seg->end)
break;
m = &seg->first_page[atop(pa - seg->start)];
if (m->order != VM_NFREEORDER - 1)
break;
}
/* If not, continue to the next block. */
if (pa < pa_last)
continue;
}
/*
* Determine if the blocks are within the given range,
* satisfy the given alignment, and do not cross the
* given boundary.
*/
pa = VM_PAGE_TO_PHYS(m_ret);
if (pa >= low &&
pa + size <= high &&
(pa & (alignment - 1)) == 0 &&
((pa ^ (pa + size - 1)) & ~(boundary - 1)) == 0)
goto done;
}
}
}
}
return (NULL);
done:
for (m = m_ret; m < &m_ret[npages]; m = &m[1 << oind]) {
fl = (*seg->free_queues)[m->pool];
TAILQ_REMOVE(&fl[m->order].pl, m, pageq);
fl[m->order].lcnt--;
m->order = VM_NFREEORDER;
}
if (m_ret->pool != VM_FREEPOOL_DEFAULT)
vm_phys_set_pool(VM_FREEPOOL_DEFAULT, m_ret, oind);
fl = (*seg->free_queues)[m_ret->pool];
vm_phys_split_pages(m_ret, oind, fl, order);
Eliminate vm_phys_bootstrap_alloc(). It was a failed attempt at eliminating duplicated code in the various pmap implementations. Micro-optimize vm_phys_free_pages(). Introduce vm_phys_free_contig(). It is fast routine for freeing an arbitrary number of physically contiguous pages. In particular, it doesn't require the number of pages to be a power of two. Use "u_long" instead of "unsigned long". Bruce Evans (bde@) has convinced me that the "boundary" parameters to kmem_alloc_contig(), vm_phys_alloc_contig(), and vm_reserv_reclaim_contig() should be of type "vm_paddr_t" and not "u_long". Make this change.
2011-10-30 05:06:14 +00:00
/* Return excess pages to the free lists. */
npages_end = roundup2(npages, 1 << imin(oind, order));
if (npages < npages_end)
vm_phys_free_contig(&m_ret[npages], npages_end - npages);
Add a new physical memory allocator. However, do not yet connect it to the build. This allocator uses a binary buddy system with a twist. First and foremost, this allocator is required to support the implementation of superpages. As a side effect, it enables a more robust implementation of contigmalloc(9). Moreover, this reimplementation of contigmalloc(9) eliminates the acquisition of Giant by contigmalloc(..., M_NOWAIT, ...). The twist is that this allocator tries to reduce the number of TLB misses incurred by accesses through a direct map to small, UMA-managed objects and page table pages. Roughly speaking, the physical pages that are allocated for such purposes are clustered together in the physical address space. The performance benefits vary. In the most extreme case, a uniprocessor kernel running on an Opteron, I measured an 18% reduction in system time during a buildworld. This allocator does not implement page coloring. The reason is that superpages have much the same effect. The contiguous physical memory allocation necessary for a superpage is inherently colored. Finally, the one caveat is that this allocator does not effectively support prezeroed pages. I hope this is temporary. On i386, this is a slight pessimization. However, on amd64, the beneficial effects of the direct-map optimization outweigh the ill effects. I speculate that this is true in general of machines with a direct map. Approved by: re
2007-06-10 00:49:16 +00:00
return (m_ret);
}
#ifdef DDB
/*
* Show the number of physical pages in each of the free lists.
*/
DB_SHOW_COMMAND(freepages, db_show_freepages)
{
struct vm_freelist *fl;
int flind, oind, pind;
for (flind = 0; flind < vm_nfreelists; flind++) {
db_printf("FREE LIST %d:\n"
"\n ORDER (SIZE) | NUMBER"
"\n ", flind);
for (pind = 0; pind < VM_NFREEPOOL; pind++)
db_printf(" | POOL %d", pind);
db_printf("\n-- ");
for (pind = 0; pind < VM_NFREEPOOL; pind++)
db_printf("-- -- ");
db_printf("--\n");
for (oind = VM_NFREEORDER - 1; oind >= 0; oind--) {
db_printf(" %2.2d (%6.6dK)", oind,
1 << (PAGE_SHIFT - 10 + oind));
for (pind = 0; pind < VM_NFREEPOOL; pind++) {
fl = vm_phys_free_queues[flind][pind];
db_printf(" | %6.6d", fl[oind].lcnt);
}
db_printf("\n");
}
db_printf("\n");
}
}
#endif
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